Quiz 6- Hypothesis Testing

Read the z statistic from the normal distribution table and circle the correct answer. A one-tailed test (lower tail) at a .063 level of significance; z =

-1.53

Exhibit 9-5 n= 16 X-bar= 75.607 s= 8.246 H0: Mu greater than or equal to 80 Ha: Mu less than 80 Assume population is normally distributed The p-value is equal to

0.0250

Read the t statistic from the table of t distribution and circle the correct answer. A one-tailed test (upper tail), a sample size of 18 at a .05 level of significance t=

1.740

Exhibit 9-1 n= 36 x bar= 24.6 sigma= 12 H0: Mu less than or equal to 20 ha: Mu greater than 20 The test statistic equals

2.3

Your investment executive claims that the average yearly rate of return on the stocks she recommends is at least 10.0%. You plan on taking a sample to test her claim. The correct set of hypotheses is

H0: Mu greater than or less than 10.0% Ha: Mu less than 10.0%

The average life expectancy of tires produced by the Whitney Tire Company has been 40,000 miles. Management believes that due to a new production process, the life expectancy of its tires has increased. In order to test the validity of this belief, the correct set of hypotheses is

H0: Mu less than or greater to 40,000 Ha: Mu greater than 40,000

The school's newspaper reported that the proportion of students majoring in business is at least 30%. You plan on taking a sample to test the newspaper's claim. The correct set of hypothesis is

H0: p greater than or equal to 0.30 Ha: p less than 0.30

In the past 75% of the tourists who visited Chattanooga went to see Rock City. The management of Rock City recently undertook an extensive promotional campaign. They are interested in determining whether the promotional campaign actually increased the proportion of tourists visiting Rock City. The correct set of hypotheses is

H0: p less than or equal to 0.75 Ha: p greater than 0.75

When using Excel to calculate a p-value for a lower-tail hypothesis test, the following must be used

NORM.S.DIST

Which Excel function would not be appropriate to use when conducting a hypothesis test for a population proportion?

STDEV

Exhibit 9-6 A random sample of 100 people was taken. Eighty of the people in the sample favored Candidate A. We are interested in determining whether or not the proportion of the population in favor of Candidate A is significantly more then 75% At the .05 level of significance, it can be concluded that the proportion of the population in favor of candidate A is

Significantly greater than 75%

Excel's _____ function can be used to calculate a p-value for a hypothesis test when sigma is unknown

T.DIST

In hypothesis testing, the critical value is

a number that establishes the boundary of the rejection region

A Type II error is committed when

a true alternative hypothesis is mistakenly rejected

A Type I error is committed when

a true null hypothesis is rejected

If a hypothesis is not rejected at a 5% level of significance, it will

also not be rejected at the 1% level

As a general guideline, the research hypothesis should be stated as the

alternative hypothesis

Exhibit 9-1 n= 36 x bar= 24.6 sigma= 12 H0: Mu less than or equal to 20 ha: Mu greater than 20 If the test is done at a .05 level of significance, the null hypothesis should

be rejected

For a two-tailed test with a sample size of 40, the null hypothesis will not be rejected at a 5% level of significance if the test statistic is

between -1.96 and 1.96, exclusively

When the hypotheses H0: Mu greater than or equal to 100 and Ha: Mu less than 100 are being tested at a level of significance of alpha, the null hypothesis will not be rejected if the test statistic z is

greater than -Za

A two-tailed test is a

hypothesis test in which rejection region is in both tails of the sampling distribution

A one-tailed test is a

hypothesis test in which rejection region is in one tail of the sampling distribution

If the cost of a Type I error is high, a smaller value should be chosen for the

level of significance

If a hypothesis is rejected at a 5% level of significance, it

may be rejected or not rejected at the 1% level

Two approaches to drawing a conclusion in a hypothesis test are

p-value and critical value

When the p-value is used for hypothesis testing, the null hypothesis is rejected if

p-value less than or greater to alpha

A p-value is the

probability, when the null hypothesis is true, of obtaining a sample result that is at least as unlikely as what is observed

In hypothesis testing if the null hypothesis has been rejected when the alternative hypothesis has been true,

the correct decision has been made

In hypothesis testing, the alternative hypothesis is

the hypothesis concluded to be true if the null hypothesis is rejected

in the hypothesis testing procedure, alpha is

the level of significance