A light bulb manufacturer guarantees that the mean life of a certain type of light bulb is at least 775 hours. A random sample of 20 light bulbs has a mean life of 760 hours. Assume the population is normally distributed and the population standard deviation is 58 hours. At α=0.08, do you have enough evidence to reject the manufacturer's claim? Complete parts (a) through (e). A. Identify the null hypothesis and alternative hypothesis. A.H0:μ=760 Ha:μ≠760(claim) B.H0:μ≥775(claim) Ha:μ<775 C.H0:μ≤760 Ha:μ>760(claim) D.H0:μ>775 Ha:μ≤775(claim) E.H0:μ<760(claim) Ha:μ≥760 F.H0:μ≠775(claim) Ha:μ= (b) Identify the critical value(s). Use technology. z0=_____(Use a comma to separate answers as needed. Round to two decimal places as needed.) Identify the rejection region(s). (c) Identify the standardized test statistic. Use technology. z= ___________(Round to two decimal places as needed.) (d) Decide whether to reject or fail to reject the null hypothesis, and (e) interpret the decision in the context of the original claim. A. Fail to reject H0. There is not sufficient evidence to reject the claim that mean bulb life is at least 775 hours. B. Reject H0. There is not sufficient evidence to reject the claim that mean bulb life is at least 775 hours. C. Reject H0. There is sufficient evidence to reject the claim that mean bulb life is at least 775 hours. D. Fail to reject H0. There is sufficient evidence to reject the claim that mean bulb life is at least 775 hours.
A light bulb manufacturer guarantees that the mean life of a certain type of light bulb is at least 775
hours. A random sample of 20 light bulbs has a mean life of 760 hours. Assume the population is
A. Identify the null hypothesis and alternative hypothesis.
A.H0:μ=760
Ha:μ≠760(claim)
B.H0:μ≥775(claim)
Ha:μ<775
C.H0:μ≤760
Ha:μ>760(claim)
D.H0:μ>775
Ha:μ≤775(claim)
E.H0:μ<760(claim)
Ha:μ≥760
F.H0:μ≠775(claim)
Ha:μ=
(b) Identify the critical value(s). Use technology.
z0=_____(Use a comma to separate answers as needed. Round to two decimal places as needed.)
Identify the rejection region(s).
(c) Identify the standardized test statistic. Use technology.
z= ___________(Round to two decimal places as needed.)
(d) Decide whether to reject or fail to reject the null hypothesis, and (e) interpret the decision in the context of the original claim.
A. Fail to reject H0. There is not sufficient evidence to reject the claim that mean bulb life is at least 775 hours.
B. Reject H0. There is not sufficient evidence to reject the claim that mean bulb life is at least 775 hours.
C. Reject H0. There is sufficient evidence to reject the claim that mean bulb life is at least 775 hours.
D. Fail to reject H0. There is sufficient evidence to reject the claim that mean bulb life is at least 775 hours.
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