Question
If anyone can help with these quick questions, I'd reallyappreciate it. Will rate : ) 2. Forty-five CEOs from the electronics industry were randomlysampled anda 99% confidence interval for the average salaryof all electronics CEOs was constructed. The interval was ($101866,115016). To make more useful inferences from the data, it isdesired to reduce the width of the confidence interval. What twoways will result in a reduced interval width? __________ SampleSize and _________ Confidence Interval (a). Increase, Increase (b). Decrease, Increase (c).Decrease, Decrease (d). Increase, Decrease 3. Suppose a 95% confidence interval for the population meanturns out to be (1000, 2100). If this interval was based on asample size of n = 22, explain what assumption is necessary forthis interval to be valid. (a). The sampling distribution must be biased with 21 degreesof freedom. (b). The sampling distribution of the sample mean must have anormal distribution. (c). The population must have an approximately normaldistribution. (d). The population must have an approximate tdistribution. If anyone can help with these quick questions, I'd reallyappreciate it. Will rate : ) 2. Forty-five CEOs from the electronics industry were randomlysampled anda 99% confidence interval for the average salaryof all electronics CEOs was constructed. The interval was ($101866,115016). To make more useful inferences from the data, it isdesired to reduce the width of the confidence interval. What twoways will result in a reduced interval width? __________ SampleSize and _________ Confidence Interval (a). Increase, Increase (b). Decrease, Increase (c).Decrease, Decrease (d). Increase, Decrease 3. Suppose a 95% confidence interval for the population meanturns out to be (1000, 2100). If this interval was based on asample size of n = 22, explain what assumption is necessary forthis interval to be valid. (a). The sampling distribution must be biased with 21 degreesof freedom. (b). The sampling distribution of the sample mean must have anormal distribution. (c). The population must have an approximately normaldistribution. (d). The population must have an approximate tdistribution.
Explanation / Answer
2. The answer is d.; increasing thesample size wil decrease the variability of the samples obtained,so they can be closer to the true parameter and decreasing theconfidence level will give you a higher chance that the parameteris outside the interval, but the interval will be smaller. 3. b. In accordancewith the central limit theorem, the sampling distribution ofsample mean needs to be approximately normally distributed forconfidence intervals to be valid.