At western university the historical mean of scholarship examination scores for freshman applications is 900. a historical population standard deviation s=180 is assumed known each year, the assistant dean uses a sample of applications to determine whether the mean examination score for the new freshman applications has changed.
- state the hypotheses
- what is the 95% confidence interval estimate of the population mean examination score if a sample of 200 applications provided a sample mean of xbar=935 ?
- use the confidence interval to conduct a hypthesis test. using a=.05, what is your conclusion ?
- what is the p-value ?

(co 3) the soup produced by a company has a salt level that is normally distributed with a mean of 5.4 grams and a standard deviation of 0.3 grams. the company takes readings of every 10th bar off the production line. the reading points are 5.8, 5.9, 4.9, 6.5, 5.0, 4.9, 6.2, 5.1, 5.7, 6.1. is the process in control or out of control and why? it is out of control as two of these data points are more than 2 standard deviations from the mean it is in control as the data points more than 2 standard deviations from the mean are far apart it is out of control as one of these data points is more than 3 standard deviations from the mean it is in control as the values jump above and below the mean