q1. the manager of the quality department for a tire manufacturing company wants to know the average tensile strength of rubber used in making a certain brand of radial tire. The population is normally distributed and the population standard deviation is known. She uses a Z test to test the null hypothesis that the mean tensile strength is 800 pounds per square inch. The calculated Z test statistic is a positive value that leads to a p-value of .045 for the test. If the significance level () is .01, the null hypothesis would not be rejected.

True or False

q2. The fill weight of a certain brand of adult cereal is normally distributed with a mean of 910 grams and a standard deviation of 5 grams. If we select one box of cereal at random from this population, what is the probability that it will weigh more than 904 grams?

a. 0.3849

b. 0.1151

c. 0.2302

d. 0.8849

e. 0.7698

q3. The width of a confidence interval will be:

a. narrower for 99% confidence than for 90% confidence

b. none of the above

c. wider for a 99% confidence than for 95% confidence

d. narrower for sample size of 25 than for a sample size of 36

e. wider for a sample size of 64 than for a sample size of 36

q4. Which one of the following statements is not an essential assumption of the binomial distribution?

a. sampling is with replacement

b. each trial results in one of two mutually exclusive outcomes

c. the experiment consists of n identical trials

d. trials are independent of each other

e. the probability of success remains constant from trial to trial

q5. A sample statistic is a consistent estimate of a population parameter if the mean of the populations of all possible values of the sample statistic equals the population parameter.

True or False

q6. As the level of significance increases, we are more likely to reject the null hypothesis

True or False

q7. As the sample size increases, the standard deviation of the sampling distribution decreases

True or False

q8. A fair die with six faces is rolled 10 times. What is the probability that an even number (2,4, or 6) will occur between 2 and 4 times (inclusive)?

a. 0.6123

b. 0.3662

c. 0.3223

d. 0.1709

e. 0.1611

q9. All of the following are assumptions of the error terms in the simple linear regression model except:

a. error terms are dependent on each other

b. error terms have a constant variance

c. error terms have a mean zero

d. errors are normally distributed

e. error terms are uncorrelated with the explanatory variable

q10. A sample statistic is an unbiased point estimate of a population parameter if every sample value of the sample statistic equals the population parameter.

True or False