statistics homework 1
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Homework 1 #3
Class Name : MAT2058 Statistics (10wk) - 20200627 - MAT2058 Statistics VB05
Instructor Name : Bibi
Student Name : _____________________ Instructor Note :
Question 1 of 9
The total blood cholesterol level was measured for each of adults. Here are the measurements (in mg/dL).
, , , , , , , , , , , , , , , , , , , ,
Question 2 of 9
21 21
132 142 151 154 167 173 183 183 183 186 187 191 195 196 196 202 202 214 223 227 244
Frequency
Cholesterol level (in mg/dL)
10
8
6
4
2
0
2
4
9
4
2
125 150 175 200 225 250
(a) For these data, which measures of central tendency take more than one value? Choose all that apply.
Mean
Median
Mode
None of these measures
(b) Suppose that the measurement 132 (the smallest measurement in the data set) were replaced by 51. Which measures of central tendency would be affected by the change? Choose all that apply.
Mean
Median
Mode
None of these measures
(c) Suppose that, starting with the original data set, the smallest measurement were removed. Which measures of central tendency would be changed from those of the original data set? Choose all that apply.
Mean
Median
Mode
None of these measures
(d) Which of the following best describes the distribution of the original data? Choose only one.
Negatively skewed
Positively skewed
Roughly symmetrical
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A survey of adults employed full-time was taken. Here are their reported numbers of hours worked per week.
, , , , , , , , , , , , , , , , , , , ,
Question 3 of 9
36 37 38 38 38 39 39 39 39 41 41 41 42 42 42 43 44 46 49 53 58
Frequency
Number of hours worked per week
10
8
6
4
2
0
9 8
2 1 1
35 40 45 50 55 60
(a) Which measures of central tendency do not exist for this data set? Choose all that apply.
Mean
Median
Mode
None of these measures
(b) Suppose that the measurement 58 (the largest measurement in the data set) were replaced by 101. Which measures of central tendency would be affected by the change? Choose all that apply.
Mean
Median
Mode
None of these measures
(c) Suppose that, starting with the original data set, the smallest measurement were removed. Which measures of central tendency would be changed from those of the original data set? Choose all that apply.
Mean
Median
Mode
None of these measures
(d) The relative values of the mean and median for the original data set are typical of data that have a significant skew to the right. What are the relative values of the mean and median for the original data set? Choose only one.
Mean is greater
Median is greater
Cannot be determined
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Four distributions, labeled (a), (b), (c), and (d), are represented below by their histograms. Each distribution is made of
measurements. Without performing any calculations, order their respective means , , , and .
Question 4 of 9
On each trial of an experiment, a participant is presented with a constant soft noise, which is interrupted at some unpredictable time by a slightly louder sound. The time it takes for the participant to react to the louder sound is recorded. The following list contains the reaction times (in milliseconds) for trials of this experiment:
(a) What is the mean of this data set? If your answer is not an integer, round your answer to one decimal place.
(b) What is the median of this data set? If your answer is not an integer, round your answer to one decimal place.
(c) How many modes does the data set have, and what are their values? Indicate the number of modes by selecting the appropriate line, and then indicate the value(s) of the mode(s), if applicable.
1. zero modes 2. one mode: _____ 3. two modes: _____ _____
Question 5 of 9
9 μa μb μc μd
8
404, 334, 404, 404, 465, 738, 478, 510
1 2 3 4 5 6 7 8 9 10 11 12 13 14
(a)
1 2 3 4 5 6 7 8 9 10 11 12 13 14
(b)
1 2 3 4 5 6 7 8 9 10 11 12 13 14
(c)
1 2 3 4 5 6 7 8 9 10 11 12 13 14
(d)
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A professional golfer is shopping for a new brand of golf ball. He likes most of the features of one particular brand, but he wants to make sure that the brand has a desirable spin rate (the rate at which the ball spins on its axis after being struck by a golf club). He estimates that the ideal ball has a spin rate of about revolutions per minute for a five-iron shot. To
test the spin rate of this new brand of ball, the golfer hits the brand of ball on five-iron shots, and a computer measures
the spin rate for each shot. The computer then produces the following histogram summarizing the spin rates:
Based on the histogram, estimate the mean spin rate (in revolutions per minute) for the sample of five-iron shots. Carry your intermediate computations to at least four decimal places, and round your answer to the nearest integer.
Question 6 of 9
The following are all quiz scores of a student in a statistics course. Each quiz was graded on a 10-point scale.
Assuming that these scores constitute an entire population, find the standard deviation of the population. Round your answer to two decimal places.
(If necessary, consult a list of formulas.)
Question 7 of 9
Find the standard deviation of this sample of counts. Round your answer to two decimal places.
(If necessary, consult a list of formulas.)
Question 8 of 9
7000 73
73
Frequency
Spin rate (in revolutions per minute)
20
15
10
5
0
3
12 14
20 18
6
5000 5500 6000 6500 7000 7500 8000
6
10, 5, 9, 5, 6, 7
54, 48, 53, 55, 51, 51
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For each of the variables described below, indicate whether it is a quantitative or a categorical (qualitative) variable. Also, indicate the level of measurement for the variable: nominal, ordinal, interval, or ratio. Make sure your responses are the most specific possible.
Indicate your choice for each by circling the appropriate answer.
Variable Type of variable Level of measurement
(a) Highest educational degree completed (less than high school diploma, high school diploma, two-year college degree, four-year college degree, or graduate degree)
Quantitative Categorical
Nominal Ordinal Interval Ratio
(b) Temperature (in degrees Fahrenheit) Quantitative Categorical
Nominal Ordinal Interval Ratio
(c) Amount (in pounds) of weight needed to break a bridge cable QuantitativeCategorical
Nominal Ordinal Interval Ratio
Question 9 of 9
Which of the following variables are best thought of as continuous, which discrete? Indicate your choice for each by circling the appropriate answer.
(a) The number of occupied tables at Zito's Cafe at p.m. next Friday.
Discrete Continuous
(b) The number of personal-injury traffic accidents last week on Interstate in Indiana.
Discrete Continuous
(c) The height of a fifth-grade boy.
Discrete Continuous
(d) The score (either , , , or , with being the worst and being the best) given by a quality-control manager after an equipment inspection.
Discrete Continuous
8
65
0 1 2 3 0 3