stats help
Question 1
| Lower Limit | Upper Limit | |||||||||
| p = | 0.25 | x0 = | 0.8 | x0 = | 0.92 | 0.03980 | ||||
| n = | 24 | n = | 25 | 0.02967 | ||||||
| Confidence Level | S(x0) = | 2 | S(x0) = | 10 | ||||||
| 0.9305 | P[X ≤ x0] = | 0.0398011873 | P[X ≤ x0] = | 0.9703300881 | 0.0296699119 | |||||
| 93.0528900722 | LowerLimit = | 0.8 | Upper Limit = | 0.92 | ||||||
| Treatment 2 | x - x0 | Sign | x - x0 | Sign | ||||||
| 0.76 | -0.04 | - | -0.16 | - | ||||||
| 0.79 | -0.01 | - | -0.13 | - | ||||||
| 0.8 | 0 | tie | -0.12 | - | ||||||
| 0.81 | 0.01 | + | -0.11 | - | ||||||
| 0.81 | 0.01 | + | -0.11 | - | ||||||
| 0.82 | 0.02 | + | -0.1 | - | ||||||
| 0.89 | 0.09 | + | -0.03 | - | ||||||
| 0.9 | 0.1 | + | -0.02 | - | ||||||
| 0.9 | 0.1 | + | -0.02 | - | ||||||
| 0.91 | 0.11 | + | -0.01 | - | ||||||
| 0.93 | 0.13 | + | 0.01 | + | ||||||
| 0.93 | 0.13 | + | 0.01 | + | ||||||
| 0.94 | 0.14 | + | 0.02 | + | ||||||
| 0.94 | 0.14 | + | 0.02 | + | ||||||
| 0.94 | 0.14 | + | 0.02 | + | ||||||
| 0.95 | 0.15 | + | 0.03 | + | ||||||
| 0.95 | 0.15 | + | 0.03 | + | ||||||
| 0.95 | 0.15 | + | 0.03 | + | ||||||
| 0.96 | 0.16 | + | 0.04 | + | ||||||
| 0.97 | 0.17 | + | 0.05 | + | ||||||
| 0.97 | 0.17 | + | 0.05 | + | ||||||
| 0.97 | 0.17 | + | 0.05 | + | ||||||
| 0.97 | 0.17 | + | 0.05 | + | ||||||
| 0.99 | 0.19 | + | 0.07 | + | ||||||
| 0.99 | 0.19 | + | 0.07 | + | ||||||
| T1 | T2 | 1 | 0.78 | 0.76 | ||||||
| 1 | 0.78 | 0.76 | 2 | 0.79 | 0.79 | |||||
| 2 | 0.79 | 0.79 | 3 | 0.87 | 0.8 | |||||
| 3 | 0.87 | 0.8 | 4 | 0.91 | 0.81 | |||||
| 4 | 0.91 | 0.81 | 5 | 0.92 | 0.81 | |||||
| 5 | 0.92 | 0.81 | 6 | 0.92 | 0.82 | |||||
| 6 | 0.92 | 0.82 | 7 | 0.92 | 0.89 | |||||
| 7 | 0.92 | 0.89 | 8 | 0.93 | 0.9 | |||||
| 8 | 0.93 | 0.9 | 9 | 0.94 | 0.9 | |||||
| 9 | 0.94 | 0.9 | 10 | 0.95 | 0.91 | |||||
| 10 | 0.95 | 0.91 | 11 | 0.95 | 0.93 | |||||
| 11 | 0.95 | 0.93 | 12 | 0.95 | 0.93 | |||||
| 12 | 0.95 | 0.93 | 13 | 0.95 | 0.94 | |||||
| 13 | 0.95 | 0.94 | 14 | 0.96 | 0.94 | |||||
| 14 | 0.96 | 0.94 | 15 | 0.96 | 0.94 | |||||
| 15 | 0.96 | 0.94 | 16 | 0.96 | 0.95 | |||||
| 16 | 0.96 | 0.95 | 17 | 0.97 | 0.95 | |||||
| 17 | 0.97 | 0.95 | 18 | 0.97 | 0.95 | |||||
| 18 | 0.97 | 0.95 | 19 | 0.97 | 0.96 | |||||
| 19 | 0.97 | 0.96 | 20 | 0.99 | 0.97 | |||||
| 20 | 0.99 | 0.97 | 21 | 0.99 | 0.97 | |||||
| 21 | 0.99 | 0.97 | 22 | 0.99 | 0.97 | |||||
| 22 | 0.99 | 0.97 | 23 | 0.99 | 0.97 | |||||
| 23 | 0.99 | 0.97 | 24 | 0.99 | 0.99 | |||||
| 24 | 0.99 | 0.99 | 25 | 0.99 | 0.99 | |||||
| 25 | 0.99 | 0.99 |
Question 2
| Empirical cdf | |||||||
| Treatment 1 | Soil Compressibility, X | Rank | Sorted values | F̂(x(i)) | |||
| x | i | x(i) | |||||
| 0.78 | 1 | 0.78 | 0.0200 | ||||
| 0.79 | 2 | 0.79 | 0.0600 | ||||
| 0.87 | 3 | 0.87 | 0.1000 | ||||
| 0.91 | 4 | 0.91 | 0.1400 | ||||
| 0.92 | 5 | 0.92 | 0.1800 | ||||
| 0.92 | 6 | 0.92 | 0.2200 | ||||
| 0.92 | 7 | 0.92 | 0.2600 | ||||
| 0.93 | 8 | 0.93 | 0.3000 | ||||
| 0.94 | 9 | 0.94 | 0.3400 | <--1 more than | 0.6600 | ||
| 0.95 | 10 | 0.95 | 0.3800 | ||||
| 0.95 | 11 | 0.95 | 0.4200 | ||||
| 0.95 | 12 | 0.95 | 0.4600 | ||||
| 0.95 | 13 | 0.95 | 0.5000 | ||||
| 0.96 | 14 | 0.96 | 0.5400 | ||||
| 0.96 | 15 | 0.96 | 0.5800 | ||||
| 0.96 | 16 | 0.96 | 0.6200 | ||||
| 0.97 | 17 | 0.97 | 0.6600 | ||||
| 0.97 | 18 | 0.97 | 0.7000 | ||||
| 0.97 | 19 | 0.97 | 0.7400 | ||||
| 0.99 | 20 | 0.99 | 0.7800 | ||||
| 0.99 | 21 | 0.99 | 0.8200 | ||||
| 0.99 | 22 | 0.99 | 0.8600 | ||||
| 0.99 | 23 | 0.99 | 0.9000 | ||||
| 0.99 | 24 | 0.99 | 0.9400 | ||||
| 0.99 | 25 | 0.99 | 0.9800 | ||||
Empirical or Actual Distribution
0.78 0.79 0.87 0.91 0.92 0.92 0.92 0.93 0.94 0.95 0.95 0.95 0.95 0.96 0.96 0.96 0.97 0.97 0.97 0.99 0.99 0.99 0.99 0.99 0.99 0.02 0.06 0.1 0.14000000000000001 0.18 0.22 0.26 0.3 0.34 0.38 0.42 0.46 0.5 0.54 0.57999999999999996 0.62 0.66 0.7 0.74 0.78 0.82 0.86 0.9 0.94 0.98Soil Compressibility, x
F̂(x(i))
Question 3
| 9 | 0 | Lower Limit | Upper Limit | ||||||||||||||||||||||||||||
| Lower Limit | Upper Limit | 9 | 1.1 | p = | 0.75 | x0 = | 0.93 | x0 = | 0.99 | ||||||||||||||||||||||
| p = | 0.75 | x0 = | 0.95 | x0 = | 0.99 | n = | 23 | n = | 23 | 0.96 | |||||||||||||||||||||
| n = | 21 | n = | 19 | 19 | 0 | Confidence Level | S(x0) = | 10 | S(x0) = | 23 | |||||||||||||||||||||
| Confidence Level | S(x0) = | 9 | S(x0) = | 19 | 19 | 1.1 | 0.9988 | P[X ≤ x0] = | 0.0012431137 | P[X ≤ x0] = | 1 | ||||||||||||||||||||
| 0.9983 | P[X ≤ x0] = | 0.0016870791 | P[X ≤ x0] = | 1 | 99.8756886342 | LowerLimit = | 0.93 | Upper Limit = | 0.99 | ||||||||||||||||||||||
| 99.8312920899 | LowerLimit = | 0.95 | Upper Limit = | 0.99 | |||||||||||||||||||||||||||
| Binomial Distribution | |||||||||||||||||||||||||||||||
| Binomial Distribution | Golfer | Standard Ball, X (Yards) | x - x0 | Sign | x - x0 | Sign | x0 | S(x0) | Probability | ||||||||||||||||||||||
| Golfer | Standard Ball, X (Yards) | x - x0 | Sign | x - x0 | Sign | x0 | S(x0) | Probability | 0.76 | -0.17 | - | -0.23 | - | 0.76 | 1 | 0 | |||||||||||||||
| 0.78 | -0.17 | - | -0.21 | - | 0.78 | 1 | 0 | 0.79 | -0.14 | - | -0.2 | - | 0.79 | 2 | 0 | ||||||||||||||||
| 0.79 | -0.16 | - | -0.2 | - | 0.79 | 2 | 0 | 0.8 | -0.13 | - | -0.19 | - | 0.8 | 3 | 0.0000000001 | ||||||||||||||||
| 0.87 | -0.08 | - | -0.12 | - | 0.87 | 3 | 0.0000000001 | 0.81 | -0.12 | - | -0.18 | - | 0.81 | 4 | 0.000000001 | ||||||||||||||||
| 0.91 | -0.04 | - | -0.08 | - | 0.91 | 4 | 0.000000001 | 0.81 | -0.12 | - | -0.18 | - | 0.81 | 5 | 0.0000000124 | ||||||||||||||||
| 0.92 | -0.03 | - | -0.07 | - | 0.92 | 5 | 0.0000000124 | 0.82 | -0.11 | - | -0.17 | - | 0.82 | 6 | 0.0000001271 | ||||||||||||||||
| 0.92 | -0.03 | - | -0.07 | - | 0.92 | 6 | 0.0000001271 | 0.89 | -0.04 | - | -0.1 | - | 0.89 | 7 | 0.0000010608 | ||||||||||||||||
| 0.92 | -0.03 | - | -0.07 | - | 0.92 | 7 | 0.0000010608 | 0.9 | -0.03 | - | -0.09 | - | 0.9 | 8 | 0.0000073635 | ||||||||||||||||
| 0.93 | -0.02 | - | -0.06 | - | 0.93 | 8 | 0.0000073635 | 0.9 | -0.03 | - | -0.09 | - | 0.9 | 9 | 0.0000430789 | ||||||||||||||||
| 0.94 | -0.01 | - | -0.05 | - | 0.94 | 9 | 0.0000430789 | 0.91 | -0.02 | - | -0.08 | - | 0.91 | 10 | 0.0002145124 | ||||||||||||||||
| 0.95 | 0 | tie | -0.04 | - | 0.95 | 10 | 0.0002145124 | 0.93 | 0 | tie | -0.06 | - | 0.93 | 11 | 0.0009158314 | ||||||||||||||||
| 0.95 | 0 | tie | -0.04 | - | 0.95 | 11 | 0.0009158314 | 0.93 | 0 | tie | -0.06 | - | 0.93 | 12 | 0.0033704481 | ||||||||||||||||
| 0.95 | 0 | tie | -0.04 | - | 0.95 | 12 | 0.0033704481 | 0.94 | 0.01 | + | -0.05 | - | 0.94 | 13 | 0.010734298 | ||||||||||||||||
| 0.95 | 0 | tie | -0.04 | - | 0.95 | 13 | 0.010734298 | 0.94 | 0.01 | + | -0.05 | - | 0.94 | 14 | 0.0296699119 | ||||||||||||||||
| 0.96 | 0.01 | + | -0.03 | - | 0.96 | 14 | 0.0296699119 | 0.94 | 0.01 | + | -0.05 | - | 0.94 | 15 | 0.0713282627 | ||||||||||||||||
| 0.96 | 0.01 | + | -0.03 | - | 0.96 | 15 | 0.0713282627 | 0.95 | 0.02 | + | -0.04 | - | 0.95 | 16 | 0.1494376704 | ||||||||||||||||
| 0.96 | 0.01 | + | -0.03 | - | 0.96 | 16 | 0.1494376704 | 0.95 | 0.02 | + | -0.04 | - | 0.95 | 17 | 0.2734937885 | ||||||||||||||||
| 0.97 | 0.02 | + | -0.02 | - | 0.97 | 17 | 0.2734937885 | 0.95 | 0.02 | + | -0.04 | - | 0.95 | 18 | 0.4389019459 | ||||||||||||||||
| 0.97 | 0.02 | + | -0.02 | - | 0.97 | 18 | 0.4389019459 | 0.96 | 0.03 | + | -0.03 | - | 0.96 | 19 | 0.6217214884 | ||||||||||||||||
| 0.97 | 0.02 | + | -0.02 | - | 0.97 | 19 | 0.6217214884 | 0.97 | 0.04 | + | -0.02 | - | 0.97 | 20 | 0.7862590766 | ||||||||||||||||
| 0.99 | 0.04 | + | 0 | tie | 0.99 | 20 | 0.7862590766 | 0.97 | 0.04 | + | -0.02 | - | 0.97 | 21 | 0.9037859253 | ||||||||||||||||
| 0.99 | 0.04 | + | 0 | tie | 0.99 | 21 | 0.9037859253 | 0.97 | 0.04 | + | -0.02 | - | 0.97 | 22 | 0.9678914791 | ||||||||||||||||
| 0.99 | 0.04 | + | 0 | tie | 0.99 | 22 | 0.9678914791 | 0.97 | 0.04 | + | -0.02 | - | 0.97 | 23 | 0.9929762611 | ||||||||||||||||
| 0.99 | 0.04 | + | 0 | tie | 0.99 | 23 | 0.9929762611 | 0.99 | 0.06 | + | 0 | tie | 0.99 | 24 | 0.9992474565 | ||||||||||||||||
| 0.99 | 0.04 | + | 0 | tie | 0.99 | 24 | 0.9992474565 | 0.99 | 0.06 | + | 0 | tie | 0.99 | 25 | 1 | ||||||||||||||||
| 0.99 | 0.04 | + | 0 | tie | 0.99 | 25 | 1 | ||||||||||||||||||||||||
| ERROR:#NAME? | |||||||||||||||||||||||||||||||
| 0.97 |
S(x0)
Cumulative probability
x0
Question 4
| Treatment 1 | x¯ | 0.9404 | w¯ | -0.0632666465 | l = | 0.9655665148 | |||||||||||
| sx = | 0.0557135531 | sw = | 0.0627113054 | b = | 20.4588310045 | ||||||||||||
| n = | 25 | ||||||||||||||||
| Rank | Height (m) | Sorted Data | Logged Data | Empirical cdf | Normal cdf | Log Normal cdf | Weibull cdf | 0 | 0 | ||||||||
| i | xi | xi | wi = ln(xi) | F̂(x(i)) | F(x(i)) | F(x(i)) | F(x(i)) | 100 | 100 | ||||||||
| 1 | 0.99 | 0.78 | -0.2484613593 | 0.02 | 0.00 | 0.00 | 0.01 | ||||||||||
| 2 | 0.96 | 0.79 | -0.2357223335 | 0.06 | 0.00 | 0.00 | 0.02 | ||||||||||
| 3 | 0.99 | 0.87 | -0.1392620673 | 0.1 | 0.10319 | 0.11279 | 0.11 | ||||||||||
| 4 | 0.97 | 0.91 | -0.0943106795 | 0.14 | 0.29 | 0.31 | 0.26 | ||||||||||
| 5 | 0.99 | 0.92 | -0.0833816089 | 0.18 | 0.36 | 0.37 | 0.31 | ||||||||||
| 6 | 0.92 | 0.92 | -0.0833816089 | 0.22 | 0.36 | 0.37 | 0.31 | ||||||||||
| 7 | 0.92 | 0.92 | -0.0833816089 | 0.26 | 0.36 | 0.37 | 0.31 | ||||||||||
| 8 | 0.79 | 0.93 | -0.0725706928 | 0.3 | 0.43 | 0.44 | 0.37 | Normal Distribution | Log Normal Distribution | ||||||||
| 9 | 0.99 | 0.94 | -0.0618754037 | 0.34 | 0.50 | 0.50885 | 0.43871 | 1% | 0.10% | 0.01% | 1% | 0.10% | 0.01% | ||||
| 10 | 0.95 | 0.95 | -0.0512932944 | 0.38 | 0.57 | 0.58 | 0.51 | Z | 2.326347874 | 3.0902323062 | 3.7190164855 | Z | 2.326347874 | 3.0902323062 | 3.7190164855 | ||
| 11 | 0.94 | 0.95 | -0.0512932944 | 0.42 | 0.57 | 0.58 | 0.51 | V | 1.0700091058 | 1.1125678217 | 1.1475996225 | W | 0.0826216656 | 0.1305258556 | 0.1699577323 | ||
| 12 | 0.95 | 0.95 | -0.0512932944 | 0.46 | 0.57 | 0.58 | 0.51 | V | 1.0861308102 | 1.1394274 | 1.1852547522 | ||||||
| 13 | 0.97 | 0.95 | -0.0512932944 | 0.5 | 0.57 | 0.58 | 0.51 | ||||||||||
| 14 | 0.96 | 0.96 | -0.0408219945 | 0.54 | 0.64 | 0.64 | 0.59 | Weibull Distribution | |||||||||
| 15 | 0.96 | 0.96 | -0.0408219945 | 0.58 | 0.64 | 0.64 | 0.59 | 1% | 0.10% | 0.01% | |||||||
| 16 | 0.92 | 0.96 | -0.0408219945 | 0.62 | 0.64 | 0.64 | 0.59 | 99% | 100% | 100% | |||||||
| 17 | 0.99 | 0.97 | -0.0304592075 | 0.66 | 0.70 | 0.70 | 0.67 | V | 1.0404009706 | 1.061225926 | 1.0762537753 | ||||||
| 18 | 0.91 | 0.97 | -0.0304592075 | 0.7 | 0.70 | 0.70 | 0.67 | ||||||||||
| 19 | 0.93 | 0.97 | -0.0304592075 | 0.74 | 0.70 | 0.70 | 0.67 | ||||||||||
| 20 | 0.78 | 0.99 | -0.0100503359 | 0.78 | 0.81 | 0.80 | 0.81 | ||||||||||
| 21 | 0.87 | 0.99 | -0.0100503359 | 0.82 | 0.81 | 0.80 | 0.81 | ||||||||||
| 22 | 0.95 | 0.99 | -0.0100503359 | 0.86 | 0.81 | 0.80 | 0.81 | ||||||||||
| 23 | 0.99 | 0.99 | -0.0100503359 | 0.9 | 0.81 | 0.80 | 0.81 | ||||||||||
| 24 | 0.95 | 0.99 | -0.0100503359 | 0.94 | 0.81 | 0.80 | 0.81 | ||||||||||
| 25 | 0.97 | 0.99 | -0.0100503359 | 0.98 | 0.81 | 0.80 | 0.81 | ||||||||||
| 1 | 0.99 | 0.76 | |||||||||||||||
| 2 | 0.96 | 0.79 | |||||||||||||||
| 3 | 0.99 | 0.8 | |||||||||||||||
| 4 | 0.97 | 0.81 | |||||||||||||||
| 5 | 0.99 | 0.81 | |||||||||||||||
| 6 | 0.92 | 0.82 | |||||||||||||||
| 7 | 0.92 | 0.89 | |||||||||||||||
| 8 | 0.79 | 0.9 | |||||||||||||||
| 9 | 0.99 | 0.9 | |||||||||||||||
| 10 | 0.95 | 0.91 | |||||||||||||||
| 11 | 0.94 | 0.93 | |||||||||||||||
| 12 | 0.95 | 0.93 | |||||||||||||||
| 13 | 0.97 | 0.94 | |||||||||||||||
| 14 | 0.96 | 0.94 | |||||||||||||||
| 15 | 0.96 | 0.94 | |||||||||||||||
| 16 | 0.92 | 0.95 | |||||||||||||||
| 17 | 0.99 | 0.95 | |||||||||||||||
| 18 | 0.91 | 0.95 | |||||||||||||||
| 19 | 0.93 | 0.96 | |||||||||||||||
| 20 | 0.78 | 0.97 | |||||||||||||||
| 21 | 0.87 | 0.97 | |||||||||||||||
| 22 | 0.95 | 0.97 | |||||||||||||||
| 23 | 0.99 | 0.97 | |||||||||||||||
| 24 | 0.95 | 0.99 | |||||||||||||||
| 25 | 0.97 | 0.99 | |||||||||||||||
In constructing offshore and coastal defence systems one should design to an appropriate wave height. This requires a statistical analysis of extreme waves. The following data set consists of the highest sea waves in the upper Adriatic sea in Venice, Italy. The data include 18 independent storms recorded in a period of 13 months between 2005 and 2006.
1. How is this data distributed? Choose between a normal, log normal and weibull distribution. 2. Use your above choice to answer the following question. If the authorities in Venice are prepared to live with a. a 1%, b. a 0.1% or c. a 0.01% risk of flooding, what wave height should their coastal defences be designed to withstand?
Question 5
Question 6
| cdf of the normal distribution | ||||||||||||||||||||||||||||||||||||
| Empirical cdf | Method 1 | Method 2 | ||||||||||||||||||||||||||||||||||
| Sea State | F̂(x(i)) | x | F(x(i)) | x | F(x(i)) | |||||||||||||||||||||||||||||||
| 1 | 0.0277777778 | 0.82 | 0.015345582 | 0.87 | ERROR:#DIV/0! | |||||||||||||||||||||||||||||||
| 2 | 0.0833333333 | 1.54 | 1 | 1.33 | ERROR:#DIV/0! | |||||||||||||||||||||||||||||||
| 3 | 0.1388888889 | 1.59 | 1 | 1.4 | ERROR:#DIV/0! | |||||||||||||||||||||||||||||||
| 4 | 0.1944444444 | 1.92 | 1 | 1.69 | ERROR:#DIV/0! | |||||||||||||||||||||||||||||||
| 5 | 0.25 | 2.23 | 1 | 1.82 | ERROR:#DIV/0! | |||||||||||||||||||||||||||||||
| 6 | 0.3055555556 | 2.55 | 1 | 2.42 | ERROR:#DIV/0! | |||||||||||||||||||||||||||||||
| 7 | 0.3611111111 | 4.09 | 1 | 3.46 | ERROR:#DIV/0! | |||||||||||||||||||||||||||||||
| Sea State | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 24 | 25 | 8 | 0.4166666667 | 5.5 | 1 | 5.3 | ERROR:#DIV/0! | |||||
| Method 1 | 0.78 | 0.79 | 0.87 | 0.91 | 0.92 | 0.92 | 0.92 | 0.93 | 0.94 | 0.95 | 0.95 | 0.95 | 0.95 | 0.96 | 0.96 | 0.96 | 0.97 | 0.97 | 0.97 | 0.99 | 0.99 | 0.99 | 0.99 | 0.99 | 0.99 | 9 | 0.4722222222 | 5.79 | 1 | 5.87 | ERROR:#DIV/0! | |||||
| Method 2 | 0.76 | 0.79 | 0.8 | 0.81 | 0.81 | 0.82 | 0.89 | 0.9 | 0.9 | 0.91 | 0.93 | 0.93 | 0.94 | 0.94 | 0.94 | 0.95 | 0.95 | 0.95 | 0.96 | 0.97 | 0.97 | 0.97 | 0.97 | 0.99 | 0.99 | 10 | 0.5277777778 | 5.79 | 1 | 5.87 | ERROR:#DIV/0! | |||||
| 11 | 0.5833333333 | 5.91 | 1 | 6.44 | ERROR:#DIV/0! | |||||||||||||||||||||||||||||||
| Mooring Method 1 | 12 | 0.6388888889 | 7.38 | 1 | 7.41 | ERROR:#DIV/0! | ||||||||||||||||||||||||||||||
| Sample mean, x̅ = | 0.9404 | 13 | 0.6944444444 | 7.99 | 1 | 8.26 | ERROR:#DIV/0! | |||||||||||||||||||||||||||||
| Sample variance, s2 = | 0.00310 | 0.00012416 | 14 | 0.75 | 8.98 | 1 | 8.88 | ERROR:#DIV/0! | ||||||||||||||||||||||||||||
| Sample s. deviation, s = | 0.05571 | 0.0111427106 | 15 | 0.8055555556 | 9.62 | 1 | 9.77 | ERROR:#DIV/0! | ||||||||||||||||||||||||||||
| Sample size, n = | 25 | 16 | 0.8611111111 | 9.96 | 1 | 9.82 | ERROR:#DIV/0! | |||||||||||||||||||||||||||||
| 17 | 0.9166666667 | 10.75 | 1 | 10.32 | ERROR:#DIV/0! | |||||||||||||||||||||||||||||||
| a = | 0.1 | 18 | 0.9722222222 | 10.83 | 1 | 11.2 | ERROR:#DIV/0! | |||||||||||||||||||||||||||||
| 1 - a = | 0.9 | 0.00012416 | ||||||||||||||||||||||||||||||||||
| tn-1,a/2 = | 1.7108820799 | |||||||||||||||||||||||||||||||||||
| Critical Point | ||||||||||||||||||||||||||||||||||||
| (tn-1,a/2) x (s / √n) = | 0.0190638639 | |||||||||||||||||||||||||||||||||||
| 90% confidecnce level | ||||||||||||||||||||||||||||||||||||
| Lower Limit | 0.9213361361 | |||||||||||||||||||||||||||||||||||
| Upper Limit | 0.9594638639 | |||||||||||||||||||||||||||||||||||
| Mooring Method 2 | ||||||||||||||||||||||||||||||||||||
| Sample mean, x̅ = | ||||||||||||||||||||||||||||||||||||
| Sample variance, s2 = | ||||||||||||||||||||||||||||||||||||
| Sample s. deviation, s = | ||||||||||||||||||||||||||||||||||||
| Sample size, n = | ||||||||||||||||||||||||||||||||||||
| a = | ||||||||||||||||||||||||||||||||||||
| 1 - a = | ||||||||||||||||||||||||||||||||||||
| tn-1,a/2 = | ||||||||||||||||||||||||||||||||||||
| (tn-1,a/2) x (s / √n) = | ||||||||||||||||||||||||||||||||||||
| Lower Limit | ||||||||||||||||||||||||||||||||||||
| Upper Limit | ||||||||||||||||||||||||||||||||||||
An experiment was carried out on scale models in a wave tank to investigate how the choice of mooring method affected the bending stress produced in a device used to generate electricity from wave power at sea. The model system was subjected to the same sample of 18 sea states with each of the two mooring methods. The resulting data (root mean square bending moment in Newton -meters) are shown below. Construct 90% confidence intervals for the true mean bending stress associated with each type of mooring. What needs to be assumed and how well do the data meet these assumptions?
Probability Plot
Method 1 1.5345581951694647E-2 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 2.7777777777777776E-2 8.3333333333333329 E-2 0.1388888888888889 0.19444444444444445 0.25 0.30555555555555558 0.3611111111111111 0.41666666666666669 0.47222222222222221 0.52777777777777779 0.58333333333333337 0.63888888888888884 0.69444444444444442 0.75 0.80555555555555558 0.86111111111111116 0.91666666666666663 0.97222222222222221 Method 2 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 2.7777777777777776E-2 8.3333333333333329E-2 0.1388888888888889 0.19444444444444445 0.25 0.30555555555555558 0.3611111111111111 0.41666666666666669 0.47222222222222221 0.52777777777777779 0.58333333333333337 0.63888888888888884 0.69444444444444442 0.75 0.80555555555555558 0.86111111111111116 0.91666666666666663 0.97222222222222221F(x(i)) assuming X is normally distributed
F̂(x(i))
The 90% confidence intervals for the two mooring methods do overlap. There is therefore no evidence to suggest that the true (population) mean bending moments associated with each method are significantly different from each other. The methods produce bending moment measurements which on the average are not different from each other. This conclusion requires the assumption that the bending moment measurements from the two different test methods are both normally distributed as the sample size is to small to invoke the central limit theorem. The probability plot alongside suggests this assumption is not reasonable.
Question 7
| Treatment 1 | Treatment 2 | |||
| 0.78 | 0.76 | |||
| 0.79 | 0.79 | |||
| 0.87 | 0.8 | |||
| 0.91 | 0.81 | |||
| 0.92 | 0.81 | |||
| 0.92 | 0.82 | |||
| 0.92 | 0.89 | |||
| 0.93 | 0.9 | |||
| 0.94 | 0.9 | |||
| 0.95 | 0.91 | |||
| 0.95 | 0.93 | |||
| 0.95 | 0.93 | |||
| 0.95 | 0.94 | |||
| 0.96 | 0.94 | |||
| 0.96 | 0.94 | |||
| 0.96 | 0.95 | |||
| 0.97 | 0.95 | |||
| 0.97 | 0.95 | |||
| 0.97 | 0.96 | |||
| 0.99 | 0.97 | |||
| 0.99 | 0.97 | |||
| 0.99 | 0.97 | |||
| 0.99 | 0.97 | |||
| 0.99 | 0.99 | |||
| 0.99 | 0.99 | |||
| Sample mean, x̅1 = | 0.9404 | Sample mean, x̅2 = | 0.9096 | |
| Sample variance, s21 = | 0.00310 | Sample variance, s22 = | 0.00482 | |
| Sample s. deviation, s1 = | 0.05571 | Sample s. deviation, s2 = | 0.06943 | |
| Sample size, n1 = | 25 | Sample size, n2= | 25 | |
| a = | 0.01 | 0.01 | ||
| 1 - a = | 0.99 | 0.99 | ||
| tn-1,a/2 = | 2.7969395048 | 2.7969395048 | ||
| Critical Point | Critical Point | |||
| (tn-1,a/2) x (s / √n) = | 0.0311654875 | 0.038838873 | 0.0388388731 | |
| 1-a% Confidence Interval | 1-a% Confidence Interval | |||
| Lower Limit | 0.9092345125 | 1 | 0.8707611269 | |
| Upper Limit | 0.9715654875 | 1 | 0.9484388731 | |
| DO OVERLAP |
The 99% confidence intervals for the two testing methods do overlap. There is therefore no evidence to suggest that the true (population) mean thicknesses associated with each test method are significantly different from each other. The ultrasound technique produce thickness measurements which on the average are not different to those obtained from sectioning. The company can therefore safely introduce the non destructive test procedure and thereby speed up delivery times and remove the scrapping cost associated with the sectioning technique. This conclusion requires the assumption that the thickness measurements from the two different test methods are both normally distributed as the sample size is to small to invoke the central limit theorem.
Question 8
| Treatment 1 | |||||
| 0.78 | |||||
| 0.79 | |||||
| 0.87 | |||||
| 0.91 | |||||
| 0.92 | |||||
| 0.92 | |||||
| 0.92 | |||||
| 0.93 | |||||
| 0.94 | |||||
| 0.95 | |||||
| 0.95 | |||||
| 0.95 | |||||
| 0.95 | |||||
| 0.96 | |||||
| 0.96 | |||||
| 0.96 | |||||
| 0.97 | |||||
| 0.97 | |||||
| 0.97 | |||||
| 0.99 | |||||
| 0.99 | |||||
| 0.99 | |||||
| 0.99 | |||||
| 0.99 | |||||
| 0.99 | |||||
| Sample mean, x̅1 = | 0.9404 | ||||
| Sample variance, s21 = | 0.00012 | ||||
| Sample s. deviation, s1 = | 0.01114 | ||||
| Sample size, n1 = | 25 | ||||
| 35.4308390023 | |||||
| a = | 0.05 | ||||
| 1 - a = | 0.95 | ||||
| tn-1,a/2 = | 2.0638985616 | ||||
| reduced by 16% | |||||
| Critical Point | L = 2 * critical point | L 0 = L * (1-0.16) | Answer | ||
| (tn-1,a/2) x (s / √n) = | 0.0045994849 | 0.0091989697699446 | 0.00772713 | 35.4308390023 | |
| 1-a% Confidence Interval | |||||
| Lower Limit | 0.9358005151 | ||||
| Upper Limit | 0.9449994849 | ||||
Question 8 (2)
| Treatment 1 | |||||
| 0.78 | |||||
| 0.79 | |||||
| 0.87 | |||||
| 0.91 | |||||
| 0.92 | |||||
| 0.92 | |||||
| 0.92 | |||||
| 0.93 | |||||
| 0.94 | |||||
| 0.95 | |||||
| 0.95 | |||||
| 0.95 | |||||
| 0.95 | |||||
| 0.96 | |||||
| 0.96 | |||||
| 0.96 | |||||
| 0.97 | |||||
| 0.97 | |||||
| 0.97 | |||||
| 0.99 | |||||
| 0.99 | |||||
| 0.99 | |||||
| 0.99 | |||||
| 0.99 | |||||
| 0.99 | |||||
| Sample mean, x̅1 = | 0.9404 | ||||
| Sample variance, s21 = | 0.00310 | ||||
| Sample s. deviation, s1 = | 0.05571 | ||||
| Sample size, n1 = | 25 | ||||
| 35.4308390023 | |||||
| a = | 0.05 | ||||
| 1 - a = | 0.95 | ||||
| tn-1,a/2 = | 2.0638985616 | ||||
| reduced by 16% | |||||
| Critical Point | L = 2 * critical point | L 0 = L * (1-0.16) | Answer | ||
| (tn-1,a/2) x (s / √n) = | 0.0229974244 | 0.0459948488497231 | 0.03863567 | 35.4308390023 | |
| 1-a% Confidence Interval | |||||
| Lower Limit | 0.9174025756 | ||||
| Upper Limit | 0.9633974244 | ||||
Question 8 (3)
| Treatment 1 | |||||
| 0.78 | |||||
| 0.79 | |||||
| 0.87 | |||||
| 0.91 | |||||
| 0.92 | |||||
| 0.92 | |||||
| 0.92 | |||||
| 0.93 | |||||
| 0.94 | |||||
| 0.95 | |||||
| 0.95 | |||||
| 0.95 | |||||
| 0.95 | |||||
| 0.96 | |||||
| 0.96 | |||||
| 0.96 | |||||
| 0.97 | |||||
| 0.97 | |||||
| 0.97 | |||||
| 0.99 | |||||
| 0.99 | |||||
| 0.99 | |||||
| 0.99 | |||||
| 0.99 | |||||
| 0.99 | |||||
| Sample mean, x̅1 = | 0.9404 | ||||
| Sample variance, s21 = | 0.00310 | ||||
| Sample s. deviation, s1 = | 0.05571 | ||||
| Sample size, n1 = | 25 | ||||
| 35.4308390023 | |||||
| a = | 0.01 | ||||
| 1 - a = | 0.99 | ||||
| tn-1,a/2 = | 2.7969395048 | ||||
| reduced by 16% | |||||
| Critical Point | L = 2 * critical point | L 0 = L * (1-0.16) | Answer | ||
| (tn-1,a/2) x (s / √n) = | 0.0311654875 | 0.0623309750564699 | 0.05298133 | 34.6020761246 | |
| 1-a% Confidence Interval | |||||
| Lower Limit | 0.9092345125 | ||||
| Upper Limit | 0.9715654875 | ||||