In a random sample of 20 people, the mean commute time to work was 31.7 minutes and the standard deviation was 7.3 minutes. assume the population is normally distributed and use a t-distribution to construct a 95% confidence interval for the population mean mu. what is the margin of error of mu? interpret the results.

Apsychology student wishes to investigate differences in political opinions between business majors and political science majors at her college. she randomly selects 100 students from the 260 business majors and 100 students from the 180 political science majors. does this sampling plan result in a simple random sample? why or why not? no, because each group of 200 students in the sample does not have the same chance of being selected. yes, because each group of 200 students in the sample has the same chance of being selected. no, because each individual student does not have an equal chance of being selected. yes, because each individual student has the same chance of being selected.

One number is 4 less than 3 times a second number. if 3 more than two times the first number is decreased by 2 times the second number, the result is 11. use the substitution method. what is the first number?

What is the equation of the line that passes through (-3, -1) and has a slope of 2/5 ? put your answer in slope-intercept form. a y= 2/5x+1/5 b y=2/5x-1/5 c y=-2/5x-1/5