Complete Question:
The mean life of a large shipment of CFLs is equal to 7,500 hours. The population standard deviation is 1,000 hours. A random sample of 64 CFLs indicate a sample life of 7,250 hours.
1. State the Null and Alternative Hypothesis.
2. At the 0.05 level of significance, is there evidence that mean life is different from 7,500 hours.
3. Construct a 95% confidence interval estimate of the population mean life of the CFLs.
4. Compute the p-value and interpret its meaning.
Answer:
-2, (7005, 7450), 0.045
Explanation:
1).
H₀: mean of life shipment is 7500 hours
the hypothesis are outlined as follows
H₀: 7500
H₁: 7500
where, n = 64, x = 7250, 1000 hours
Test statistics:
Our conclusion from the above result is that there is sufficient evidence to say that the mean life is different from 7500 hours
2). 95% confidence Interval for the population mean is
3).
the p-value is given by