Unformatted text preview: µ < 900) Assumptions: Since n = 64, the sampling distribution of x ¯ is approximately normal. Test Statistic: α = .05 RR: z > 1.645 Calculations: Decision: Reject H o . Conclusion: There is enough evidence to indicate that the new brand of light bulbs has a mean life of more than 900 hours. The University of Minnesota should buy them. Find the P-Value of the test statistic. Since the alternative hypothesis is µ > 900, the P-Value of the test statistic is P(z > 2.00) = .5 - .4772 = .0228. If the light bulbs have a mean life of 900 hours, then the probability of a value of the sample mean at least as large as 920 occurring in random sampling is .0228. Hence, anyone willing to work at a significance level of .0228 or larger will reject the null hypothesis and conclude that the data indicates that the light bulbs have a mean life of more than 900 hours....
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- Fall '08
- Statistics, Statistical hypothesis testing, Incandescent light bulb, mean life, new brand