1. Use Excel to find the critical value of z for each hypothesis test. (Negative

Question

1. Use Excel to find the critical value of z for each hypothesis test. (Negative values should be indicated by a minus sign. Round your answers to 3 decimal places.)

(a) 9 percent level of significance, two-tailed test. Critical value of z ± ........

(b) 7 percent level of significance, right-tailed test. Critical value of z .......

(c) 4 percent level of significance, left-tailed test. Critical value of z.........

2.

GreenBeam Ltd. claims that its compact fluorescent bulbs average no more than 3.25 mg of mercury. A sample of 40 bulbs shows a mean of 3.32 mg of mercury.

State the hypotheses for a right-tailed test, using GreenBeam’s claim as the null hypothesis about the mean.

H0: = 3.25 mg vs. H1: 3.25 mg

Select one:

Assuming a known standard deviation of 0.13 mg, calculate the z test statistic to test the manufacturer’s claim. (Round your answer to 2 decimal places.)

Find the p-value. (Round intermediate calculations to 2 decimal places. Round your answer to 4 decimal places.)

GreenBeam Ltd. claims that its compact fluorescent bulbs average no more than 3.25 mg of mercury. A sample of 40 bulbs shows a mean of 3.32 mg of mercury.

Explanation / Answer

1. By excel, the required z scores will be:

a) z = ± 1.695

b) z = 1.476

c) z = -1.751

2. The statistical software output for this problem is:

One sample Z summary hypothesis test:
: Mean of population
H0 : = 3.25
HA : > 3.25
Standard deviation = 0.13

Hypothesis test results:

Hence,

Hypotheses: H0: 3.25 mg vs. H1: > 3.25 mg

Option B is correct.

b) Test statistic = 3.41

c) Yes

d) P - value = 0.0003

Related Questions

Navigate

• Browse (All)
• Browse 1
• Subjects

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.