Statistics Test

STAT 101_SEU 00967775703091 Assignment _2_2023 2_نموذج

Review Test Submission: Assignment2-STAT101- 2022-23-2nd

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Course (Current Semester - الفصل الحالي)STAT-101: Statistics *******************

Test Assignment2-STAT101-2022-23-2nd

Started 1/27/23 11:52 PM

Submitted 1/28/23 1:55 AM

Due Date 1/30/23 11:00 PM

Status Completed

Attempt Score

9.75 out of 10 points

Time Elapsed

2 hours, 3 minutes out of 5 hours

Instructions Instructions of Assignment-2(STAT-101) The display date of Assignment 2 is Wednesday, January 25,

2023, 11:00 P.M. The due date of Assignment 2 is Monday, January 30, 2023, at

11:00 PM.

Assignment 2 covers the material of Weeks 5, 7, & 8 (Chapters-6,

7 & 8)

The assignment consists of 25 questions 10T/F (0.25 marks each) and 15MCQ (0.5marks each)

Total Marks = 10

You have only one attempt.

You have a time limit of 5 hours (300 minutes). This assignment will be saved and submitted automatically when

the time (5hrs) is expired. This assignment can be saved and resumed at any point until the

time (5hrs) has expired. The time will continue to run if you leave the test.

Good luck!

Saturday, January 28, 2023 1:56:01 AM AST

STAT 101_SEU 00967775703091 Assignment _2_2023 2_نموذج

Question 1

If the total area under standard normal probability distribution is k+1, then the value

of k is zero.

True

False

Question 2

If the z-score of normal distribution is –2.50, the mean of the distribution is 35 and the

standard deviation of normal distribution is 2, then the value of X for a normal

distribution is 40.

True

False

Question 3 Given that Z is a standard normal random variable. If P(Z > k)=0.0505, then the value of k is 1.64

True

False

Question 4

A confidence interval (or interval estimate) is a range (or an interval) of values used

to estimate the true value of a population parameter.

True

False

Question 5

The sample mean is not the best point estimate of the population mean.

True

False

Question 6

If the P-value for a one-sided test for testing a mean is 0.05, then the P-value for the

corresponding two-sided test would be 0.01.

True

False

Question 7

The probability of rejecting the null hypothesis when it is true is called Level of

significance.

True

False

Question 8

The alternative hypothesis for the following claim: “A car Company claims that its new car

will average more than 40 miles per gallon in the city” is H1: µ < 40.

True

False

STAT 101_SEU 00967775703091 Assignment _2_2023 2_نموذج

Question 9

The alternative hypothesis for the following claim: “A motorbike company claims that its new

model will give an average at least 60 km/l on a long route” is Ha: µ < 60.

True

False

Question 10

If the original claim says that the mean working hours in a day are same for men and

women in a company. Then symbolically it is represented as p1 = p2.

True

False

Question 11

You are given the following hypothesis test:

H0: μ=100

H1: μ ≠ 100 The calculated test statistic z = –1.0, and the critical value of z = ±1.97. Then, the

decision would be to:

Reject H0 since z < –1.97

Reject H0 since –1.97 < z < 1.97

Fail to reject H0 since –1.97 < z < 1.97

Fail to reject H0 since z < –1.97

Question 12

A prescription allergy medicine is supposed to contain an average of 245 parts per

million (ppm) of active ingredient. The manufacturer periodically collects data to

determine if the production process is working properly. A random sample of 64 pills

has a mean of 250 ppm with a standard deviation of 12 ppm.

Let µ denotes the average amount of the active ingredient in pills of this allergy

medicine. The null and alternative hypotheses are as H0: µ = 245, Ha:µ ≠ 245. The

level of significance is 1%.

The t-test statistic is 3.33 with a P-value of 0.0014. What is the correct conclusion?

The mean amount of active ingredient in pills of this allergy medicine is equal to 245

ppm.

The mean amount of active ingredient in pills of this allergy medicine is equal to 250

ppm.

The mean amount of active ingredient in pills of this allergy medicine is not equal to 245

ppm.

The mean amount of active ingredient in pills of this allergy medicine is greater than 245

ppm.

Question 13

Among 169 Egyptian-African men, the mean systolic blood pressure was 145 mmHg

with a standard deviation of 26. The t-test statistic to conclude that the mean systolic

blood pressure for a population of Egyptian-African men is greater than 142 is

-2.5

-1.3

1.5

-1.5

STAT 101_SEU 00967775703091 Assignment _2_2023 2_نموذج

Question 14

The degree of confidence is equal to:

1-α

β

α

1-β

Question 15

When carrying out a large sample test of H0: µ0 = 50, Ha: µ0 < 50, we reject H0 at

level of significance α when the calculated test statistic is:

Greater than zα

Less than – zα

Greater than zα/2

Less than zα

Question 16

A sample of 100 body temperatures has a mean of 98.6 oF. Assume that σ is known to

be 0.5 oF. Use a 0.05 significance level to test the claim that the mean body

temperature of the population is equal to 98.5 oF, as is commonly believed. What is

the value of test statistic for this testing?

1.0

3.0

-2.0

2.0

Question 17

With H0: μ = 100, Ha: μ < 100, the test statistic is z = – 1.75. Using a 0.05

significance level, the P-value and the conclusion about null hypothesis are (Given

that P(z < 1.75) =0.9599)

0.0401; reject H0

0.9599; fail to reject H0

0.0401; fail to reject H0

0.9599; reject H0

Question 18

A passing student is failed by an examiner, it is an example of:

Type-I error

Type-II error

Best Decision

All of above

Question 19

The confidence interval, 0.548 < p < 0.834 is obtained for a population proportion, p.

The margin of error, E using these confidence interval limits is

0.143

0.286

0.691

1.382

STAT 101_SEU 00967775703091 Assignment _2_2023 2_نموذج

Question 20

If the point estimate 𝑝 ̂ is 0.8 and the lower confidence limit is 0.6, then the upper

confidence limit is:

1.0

0.7

0.6

0.4

Question 21

If the Margin of error E is 0.5 and the upper confidence limit is 9, then the lower

confidence limit is:

10

14

8

2

Question 22 Evaluate P(-1< Z< 2), where P(Z < 2)=0.9772 and P(Z< -1)=0.1587

c. -0.1359

d. 0.8185

b. 0.1359

a. -0.8185

Question 23

The normal probability distribution curve is symmetrical about mean µ. Then P(X <

μ) = P(X > μ) is equal to

0.25

0

0.50

0.75

STAT 101_SEU 00967775703091 Assignment _2_2023 2_نموذج

Question 24 Which of the following is NOT true regarding the normal distribution?

d. The points of the curve meet the X-axis at z = –3 and z = 3

b. It has a single peak

c. It is symmetrical

a. Mean, median and mode are all equal

Question 25 Assume that the thermometer readings are normally distributed with a mean of 0°C and a standard deviation of 1°C for freezing water. If one thermometer is randomly selected, find the probability that it reads (at the freezing point of water) greater than -1.75 degrees.

a. 0.0401

b. -0.9599

c. 0.9599

d. None