: A survey is planned to compare salaries of plant managers in two regions. The plan is to take a sample of 300 plant managers from each region and ask their annual salaries. Assume that previous sample statistics suggest that 0, = 02 = $3500. Are the sample sizes sufficient to produce a 99% confidence interval on -Hy having a width of only $1000? Click here to view page 1 of the standard normal distribution table. Click here to view page 2 of the standard normal distribution table. The sample sizes are not sufficient because the samples would need to be at least 651 people each, which is greater than the planned sample sizes of 300. (Round up to the nearest whole number as needed.)