A manufacturer claims that the mean lifetime, , of its light bulbs is 55 months. The...

 

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A manufacturer claims that the mean lifetime, µ, of its light bulbs is 55 months. The standard deviation of these lifetimes is 8 months. Seventy bulbs are selected at random, and their mean lifetime is found to be 56 months. Can we conclude, at the 0.05 level of significance, that the mean lifetime of light bulbs made by this manufacturer differs from 55 months? Perform a two-tailed test. Then fill in the table below. Carry your intermediate computations to at least three decimal places, and round your responses as specified in the table. (If necessary, consult a list of formulas.) The null hypothesis: The alternative hypothesis: H1 ローロ 国S口 (Choose one). 口マロ The type of test statistic: ロ+ロ ロ<ロ D>O The value of the test statistic: (Round to at least three decimal places.) The p-value: (Round to at least three decimal places.) Can we conclude that the mean lifetime of light bulbs made by this manufacturer differs from 55 months? O Yes ONo A manufacturer claims that the mean lifetime, µ, of its light bulbs is 55 months. The standard deviation of these lifetimes is 8 months. Seventy bulbs are selected at random, and their mean lifetime is found to be 56 months. Can we conclude, at the 0.05 level of significance, that the mean lifetime of light bulbs made by this manufacturer differs from 55 months? Perform a two-tailed test. Then fill in the table below. Carry your intermediate computations to at least three decimal places, and round your responses as specified in the table. (If necessary, consult a list of formulas.) The null hypothesis: The alternative hypothesis: H1 ローロ 国S口 (Choose one). 口マロ The type of test statistic: ロ+ロ ロ<ロ D>O The value of the test statistic: (Round to at least three decimal places.) The p-value: (Round to at least three decimal places.) Can we conclude that the mean lifetime of light bulbs made by this manufacturer differs from 55 months? O Yes ONo