Stat&Prob Reviewer 2

Determine the null and alternative hypotheses. “It was claimed that the average monthly income of an aircraft pilot was ₱116,714.00. A random sample of 45 pilots is selected and it is found out that the average monthly salary is ₱120,000. Using a 0.01 level of significance, can it be concluded that there is an increase in the average monthly income of pilots?”

• 𝐻𝑜: µ = ₱116, 714.00,

  𝐻𝑎: µ ≤ ₱116, 714.00

• 𝐻𝑜: µ = ₱116, 714.00,

  𝐻𝑎: µ ≠ ₱116, 714.00

• 𝐻𝑜: µ = ₱116, 714.00,

  𝐻𝑎: µ > ₱116, 714.00

• 𝐻𝑜: µ = ₱116, 714.00,

  𝐻𝑎: µ < ₱116, 714.00

What is the sample standard deviation if a simple random sample of 220 students is drawn from a population of 2,740 college students? Among the sampled students, the average IQ score is 115 with standard deviation of 10.

• 10

• 115

• 220

• 2,740

Based on the Central Limit Theorem, when the sample (n) is extremely large and the variance is unknown, what is the statistical test to be used?

• t-test

• z-test

• two-tailed test

• one-tailed test

A cellular battery manufacturer claims that his battery when fully charged has a mean life of 24 hours with a 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

• sample standard deviation

• number of sampled

• population standard deviation

The sign of the alternative hypothesis in a left-tailed test is always _________.

• equal

• less than

• not equal

• greater than

“A modern approach in the advertisement will not increase the demand for a product.”

This is an example of _______________ hypothesis.

• Null

• Mean

• alternative

• right-tailed

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

• a.t-test

• b.z-test

• c.two-tailedtest

• d.one-tailedtest

When the value of parameter has significant difference with the hypothesized value, then it is called ________________.

• a. one-tailed test

• b. null hypothesis

• c. two-tailed test

• d. alternative hypothesis

What is the alternative hypothesis in the following statement?

“The number of defective batteries produced by the company is not equal to 15 batteries a day as claimed by the manager.”

• μ=15

• μ≠15

• μ>15

• μ<15

What appropriate tool is applicable if the population is normal, sample standard deviation is known, and sample is less than 30?

• t-test

• z-test

• normal test

• Central Limit Theorem