z test and t test two sample

If the number of samples is sufficiently large and the variance is unknown, then ________________________ is appropriate to be used.

A z-score is calculated with population parameters such as population mean and ______________________.

____________ includes all of the elements from a set of data while ______________ consists of one or more observations drawn from the population.

A cellular battery manufacturer claims that his battery when fully charged has mean life of 24 hours with standard deviation of 4 hours. A dealer randomly chose sample of 35 batteries to be tested and resulted to 22.5 hours mean life. In the given situation, 22.5 hours is __________.

• sample mean

• number of sample

• sample standard deviation

• population standard deviation

A leader of an association of jeepney driver claims that the average daily take-home pay of all jeepney drivers in Caloocan is ₱350.00. A random sample of 100 jeepney drivers in Caloocan was interviewed and the take-home pay was found to be ₱420.00. If 0.05 significance level was used to find out whether the average take home pay is different from ₱350.00 and population variance was assumed to be ₱92.00, what is the appropriate test statistic?

• t-test

• z-test

• left-tailed test

• right-tailed test

A test is made of H₀ : µ = 50 versus H₁ : µ =/= 50 is performed using α = 0.01 significance level. The value of the test statistic is z = -2.68 and it is concluded that we fail to reject H₀ .

If the true value of µ is 65, is the conclusion a Type I Error, Type II error, or a correct decision?

• Type I

• Type II

• Correct Decision

If the variance is known, what test statistic is appropriate?

• t-test

• z-test

• two-tailed test

• one-tailed test

Which of the following symbols is NOT needed when t-test is used in computing values?

• 𝑛

• μ

• 𝜎

• 𝑠

5. In the two-tailed test, the rejection region lies on ___________ of the normal distribution.

• A. center

• B. left tail

• C. right tail

• D. both tails

13. Which statistical method can you use when you have a normal distribution of data?

• A. t–test only

• B. z–test only

• C. either t–test or z–test

• D. neither t–test nor z–test