GreenBeam Ltd. claims that its compact fluorescent bulbs average no more than 3.
ID: 3060015 • Letter: G
Question
GreenBeam Ltd. claims that its compact fluorescent bulbs average no more than 3.55 mg of mercury. A sample of 25 bulbs shows a mean of 3.62 mg of mercury.
(a) State the hypotheses for a right-tailed test, using GreenBeam’s claim as the null hypothesis about the mean.
a. H0: 3.55 mg vs. H1: < 3.55 mg
b. H0: 3.55 mg vs. H1: > 3.55 mg
c. H0: = 3.55 mg vs. H1: 3.55 mg
(b) Assuming a known standard deviation of 0.24 mg, calculate the z test statistic to test the manufacturer’s claim. (Round your answer to 2 decimal places.)
Test statistic:
(c) At the 2 percent level of significance ( = 0.02) does the sample exceed the manufacturer’s claim?
No
Yes
(d) Find the p-value. (Round intermediate calculations to 2 decimal places. Round your answer to 4 decimal places.)
p-value:
Explanation / Answer
The statistical software output for this problem is:
One sample Z summary hypothesis test:
: Mean of population
H0 : = 3.55
HA : > 3.55
Standard deviation = 0.24
Hypothesis test results:
Hence,
a) Hypotheses: H0: 3.55 mg vs. H1: > 3.55 mg
Option B is correct.
b) Test statistic = 1.46
c) No
d) p - Value = 0.0724
Mean n Sample Mean Std. Err. Z-Stat P-value 25 3.62 0.048 1.4583333 0.0724Related Questions
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