Answer Happy

The quality-control manager at a compact fluorescent light bulb (CFL) factory needs to determine whether the mean life of a large shipment of CFLs is equal to 7500 hours. The population standard deviation is 1,260 hours. A random sample of 81 light bulbs indicates a sample mean life of 7,192 hours. a. At the 0.05 level of significance, is there evidence that the mean life is different from 7500 hours? b. Compute the p-value and interpret its meaning, C. Construct a 95% confidence interval estimate of the population mean life of the light bulbs. d. Compare the results of (a) and (c). What conclusions do you reach? e. Compare the results of parts (a) through (d) to those when the standard deviation is 1,575 hours. *

Recently, a large academic medical center determined that 7 of 15 employees in a particular position were male, whereas 56% of the employees for this position in the general workforce were male. At the 0.01 level of significance, is there evidence that the proportion of males in this position at this medical center is different from what would be expected in the general workforce? BE What are the correct hypotheses to test to determine if the proportion is different? A. HO: AS0.56; H,: 1 > 0.56 OB. Ho: n=0.56; H,: **0.56 OC. Hin20.56; H,: <0.56 OD. H: *#0.56; H,: 1 = 0.56