Question 1(1 point)

A personnel manager gives an aptitude test to all applicants for a job. 70% of all applicants pass the test. If 8 people apply for the job, determine the probability that at most 3 of them fail the test.

Question 1 options:

.0113

.5518

.0580

.8059

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Question 2(1 point)

Which of the following statements is INCORRECT about the sampling distribution of the sample mean?

Question 2 options:

The sampling distribution shows how the sample mean will vary among repeated samples.

The sample mean does not necessarily equal the population mean.

The sampling distribution shows how the sample was distributed around the sample mean.

The average sample mean, over all possible samples, equals the population mean.

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Question 3(1 point)

A population is known to be normally distributed with a standard deviation of 20. A confidence interval estimate is constructed from a random sample of size 25 with a mean of 113.4. A second confidence interval estimate is constructed from a random sample of size 400 with a mean of 96.2. Assuming both intervals were constructed with the same confidence level, then the first interval will be _____ times wider than the second one.

Question 3 options:

2

3

4

5

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Question 4(1 point)

In a binomial distribution with a sample size of 10, it is found that P(X = 2) = 0.2816 and thatP(X = 3) = 0.2503. Then P(X = 4) is:

Question 4 options:

0.1460

0.2001

0.0881

0.1211

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Question 5(1 point)

Cans of peanuts have a stated net weight of 500g. However, due to variation in the canning process, the actual net weight has an approximate normal distribution with a mean of 505g and a standard deviation of 10g. According to Consumer Affairs, a sample of 25 cans should have less than a 5% chance that the mean weight is less than 500g. What is the actual probability that a sample of 25 cans will have a mean weight less than 500g?

Question 5 options:

0.1915

0.0062

0.3085

0.0228

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Question 6(1 point)

The provincial government claims that university graduates earn an average of $46,000 in their first year after graduation. A random sample of new graduates was selected and a 90% confidence interval was found to be ($41,227 to $44,871). This interval is interpreted to mean that:

Question 6 options:

90% of all values of the population lie in the interval.

If we were to repeat our survey many times, then about 90% of all the confidence intervals will contain the value $46,000.

There is a 90% probability that the first year earnings is between $41,227 and $44,871 for all new graduates.

If we repeat our survey many times, then about 90% of our confidence intervals will contain the true value of the average first year earnings.

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Question 7(1 point)

A marketing research department is currently conducting a study to analyze the spending of Canadian households on cleaning products. It was determined that for a sample of 42 households, the probability that the sample mean amount spent on cleaning products by households per week being less than $25 is 0.8686. It is also known that the value of the population mean is $23. What is the value of the population standard deviation?

Question 7 options:

14.92

133.93

11.57

222.67

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Question 8(1 point)

A random sample of 100 students from a high school was selected. If a 98% confidence interval estimate for the mean age of students is calculated to be 14.2511 to 14.9489, then the standard deviation of the sample mean is:

Question 8 options:

0.35

0.15

1.80

2.25

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Question 9(1 point)

Which of the following statements are false?

(A) For a continuously distributed population, the sampling distribution of the sample mean is approximately normal when the sample size is greater than thirty.

(B) The z-distribution should always be used whenever the sample is small, the population is normally distributedand the population standard deviation is known.

(C) For a fixed sample size, as confidence increases so does precision.

(D) The standard deviation of the sample mean increases as the standard deviation of the population decreases.

Question 9 options:

A and B only

B and C only

A and D only

C and D only

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Question 10(1 point)

A turkey producer knows from previous experience that profits are maximized by selling turkeys when their average weight is 12 kilograms. Before determining whether to put all their full grown turkeys on the market this month, the producer wishes to estimate their mean weight. Prior knowledge indicates that turkey weights have a standard deviation of around 2 kilograms. The number of turkeys that must be sampled in order to estimate their true mean weight to within 0.5 kilograms with 95% confidence is:

Question 10 options:

62

5

200

35

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Question 11(1 point)

A sample of 80 items is selected to determine whether or not to accept the hypothesis that a population mean differs from a value of 25. The sample mean and standard deviation are 23.5 and 6 respectively. The null hypothesis is not rejected, which of the following is a possible value for the level of significance associated with this test?

Question 11 options:

8%

10%

1%

5%

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Question 12(1 point)

Consider the test of hypothesis to determine if the population mean is more than 50 at the 1% level of significance. The sample data for the test is: n = 64,x-bar = 46, s = 15. If the probability of a Type II error is .9664, then the value of the population meanwhich satifies the alternative hypothesisis closest to:

Question 12 options:

50.9

45.6

48.6

42.2

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Question 13(1 point)

Which of the following statements are FALSE?

(A) A 98% confidence interval estimate of a population mean is 37.24 to 56.38. Then the correct conclusion for a two-tailed test with a hypothesized mean of 50, based on this confidence interval, at the 2% level of significance, must be to conclude Ho.

(B) A test of hypothesis is found to have a p-value of .086. Then one should conclude H1 if the level of significance is 5% and conclude Ho if the level of significance is 10%.

(C) In an upper-tail test, if the p-value is less than alpha, then the test statistic would be greater than the action limit or critical value.

(D) The power of a test is the probability of accepting a null hypothesis when it is false.

Question 13 options:

A and C only

B and D only

A and D only

B and C only

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Question 14(1 point)

The Dean of a university claims that no more than 10% of the students drop out of university. She chooses a random sample of 500 students and decides that she will accept the claim only if no more than 30 of the 500 students drop out of university. In fact her claim is false - the actual percentage of students who drop out of university is 11%; nevertheless the sample had 25 students who drop out. Based on the sample data the Dean would make a ________ error.

Question 14 options:

Type I

Type II

No error is being committed

Cannot be determined

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Question 15(1 point)

A VP of manufacturing claims that more than 3% of items produced using a certain assembly line are defective. A random sample of 400 items is selected. At the 10% level of significance, which of the following would be part of the standardized decision rule?

Question 15 options:

Conclude Ho if TS is greater than or equal to 1.645

Conclude Ho if TS is less than or equal to 1.282

Conclude Ho if TS is greater than or equal to 1.282

Conclude Ho if TS is less than or equal to 1.645

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