REVIEW

Which of the following is the critical of the test statistic where n = 31, 𝛼 = 10% and it follows a two-tailed test?

• a. ±1.28

• b. ±1.645

• c. ±2.33

• d. ±2.58

Which of the following is the z test statistic for the hypothesis test where n = 36, 𝑥 = 347, 𝛿 = 3, 𝜇𝑜 = 349, and 𝛼 = 0.05

• a. -3

• b. 3

• c. -4

• d. 4

Which test is applicable in the given problem? The average height of female students in a class has been recorded as 152.5 cm with a standard deviation of 6.9 cm. Is there a reason to believe that there has been a chance in the average height if a random sample of 50 female students in the present class has an average height of 165.2 cm instead?

• a. z-test

• b. t-test

Which test is applicable in the given problem? An English teacher wants to test whether the mean reading speed of students is 550 words per minute. A sample of 12 students revealed a sample mean of 540 words per minute with standard deviation of 5 words per minute. At the 0.05 significance level, is the reading speed different from 550 words per minute?

• a. z-test

• b. t-test

Which test is applicable in the given problem? A manufacturer claims that the average life of batteries use in their electronic games is 150 hrs. It is known that the standard deviation of this type of battery is 20 hrs. A consumer wishes to test the manufacturer’s claim and accordingly test 100 electronic games using this battery and found out that the mean is equal to 144 hrs. Using a 5% level of significance, test if the claim is true.

• a. z-test

• b. t-test

Which test is applicable in the given problem? The personnel department of a company has developed an aptitude test for screening potential employees. The person devised the test asserted that the mean mark attained would be 100. The following results were obtained with a random sample of applicants: 𝑥 = 96 s = 5.2 n = 13 Test the hypothesis that the mean mark is equal to 100 against the alternative that the mean mark is less than 100, at the 1% level of significance.

• a. z-test

• b. t-test

Which test is applicable in the given problem? The supervisor of a certain company claims that the mean workday of his workers is 8.5 hours per day with a standard deviation of 1 hour. A sample of 40 workers was taken and it was found out that the mean workday is 8.8 hours At the 0.01 significance level, is the mean workday more than 8.5 hours?

• a. z-test

• b. t-test

Which of the following are the null and alternative hypotheses? An English teacher wants to test whether the mean reading speed of students is 550 words per minute. A sample of 12 students revealed a sample mean of 540 words per minute with standard deviation of 5 words per minute. At the 0.05 significance level, is the reading speed different from 550 words per minute?

• HO: μ=540; HA: μ ≠540

• HO: μ=550; HA: μ < 550

• HO: μ=540; HA: μ > 540

• HO: μ=550; HA: μ ≠550

Which of the following are the null and alternative hypotheses? A manufacturer claims that the average life of batteries use in their electronic games is 150 hrs. It is known that the standard deviation of this type of battery is 20 hrs. A consumer wishes to test the manufacturer’s claim and accordingly test 100 electronic games using this battery and found out that the mean is equal to 144 hrs. Using a 5% level of significance, test if the claim is true.

• HO: μ=150; HA: μ ≠150

• HO: μ=144; HA: μ ≠ 144

• HO: μ≥150; HA: μ < 150

• HO: μ=144; HA: μ ≠144