An advertising agency would like to create an advertisement for a fast food restaurant claiming that the average waiting time from ordering to receiving your order is less than 5 minutes. The agency measured the time from ordering to serving the order for 25 customers and found that the average time was 4.7 minutes with a standard deviation of 0.6 minutes. The appropriate set of hypothesis for the test is

A. Ho: 4.7 vs. Ha: >4.7

B. Ho: 5 vs. Ha: <5

C. Ho: 4.7 vs. Ha: <4.7

D. Ho: 5 vs. Ha: >5

If P(-2 < Z < k) 0.70, where Z is a standard normal random variable, then k is

A. 0.195

B. 0.55

C. 0.59

D. 0.73

When using a statistical software such as R for hypothesis testing, the p-value is compared with the ____________________ to determine whether the null hypothesis is rejected or not.

A. critical value of the test statistic.

B. computed value of the test statistic.

C. level of significance

D. degrees of freedom.

Which of the following would indicate that a dataset is not bell-shaped?

A. The mean is much smaller than the median.

B. The range is larger than the interquartile range.

C. The range is equal to 5 standard deviations.

D. There are no outliers.

It is a rule or theorem that determines the proportion of observations that are contained within a number of standard deviations from the mean for any type of data distribution.

A. The Empirical Rule

B. The Normal Distribution

C. Chebyshev's Theorem.

D. Coefficient of Variation

A tire manufacturer claims that its tires have a mean life of at least 50,000 km. A random sample of 25 of these tires is tested and the mean life is 33,000 km. Suppose the population standard deviation is 2,500 km. and the lives of tires is approximately normal. To test the manufacturer's claim at the 5% level of significance, the analyst should

A. perform a right-tailed test using the t-statistic.

B. perform a left-tailed test using the t-statistic.

C. perform a right-tailed test using the z- statistic.

D. perform a left-tailed test using the z- statistic.

Which of the following statements are true? I. If there is sufficient evidence to reject a null hypothesis at the 10% level, then there is sufficient evidence to reject it at the 5% level. II. Whether to use a one- or two-tailed test is typically decided after the data are gathered. III. If a hypothesis test is conducted at the 1% level of significance, there is a 1% chance of rejecting the null hypothesis given that it is true.

A. Statement I only

B. Statement III only

C. Statements I and III only

D. None of the above