Fifty students are enrolled in a business statistics class. after the first examination, a random sample of 5 papers was selected. the grades were 60, 75, 80, 70, and 90. a) determine the standard error of the mean. b) what assumption must be made before we can determine an interval for the mean grade of all the students in the class? explain why. c) assume the assumption of part b is met. provide a 90% confidence interval for the mean grade of all the students in the class.

The average hourly earnings for a construction worker is projected to be $24.50 in 2012. jason wants to join the construction work force after he graduates in 2012. his friend tells him that average hourly earnings for construction workers will rise by 2% from 2009 to 2012. based on the data below, assuming that the projected hourly earnings are correct, is jason’s friend’s statement accurate? construction industry - average hourly earnings, 2000-2009 a. his friend’s statement is accurate. the average hourly earnings will increase by 2%. b. his friend’s statement is not accurate. the percent increase will be more than 2% c. his friend’s statement is not accurate. the percent increase will be less than 2% d. his friend’s statement is not accurate. the average hourly earnings will decrease

Rena is building a 1: 180 scale model of a real castle. her model has a rectangular base that is 3 feet wide and 4 feet long what is the area of the base of the actual castle in square feet

Me find the value of x each figure.