statistics
posted by Ronnie .
A sample of the number of study per week of college students is collected. Some of the sample results of the survey are given in the following table
Study Hr 4, 10, 20,24, 34, 36, 42
Z score 2.5,1.75,0.5,0, 1.25,1.5,2.25
P. Rank 10, 25, 35, 40, 50, 75 95
Q1 The mean study time for all the students
Q2 The median study time for all the student
Q3 The percent of college students who study between 20 and 36 hrs per week
Q4 The study time representing the 1st quartile
Q5 The Standard Deviation study time for all the students
Q5 The study time corresponding to a Z score of 1.75

We do not do your work for you. Once you have attempted to answer your questions, we will be happy to give you feedback on your work. Although it might require more time and effort, you will learn more if you do your own work. Isn't that why you go to school?
However, I will give you a start.
1. Z = 0 = mean
5. Z = (scoremean)/SD
Once you have found the mean, insert its value plus the Z and raw score for one student to solve for SD.
Use that data for 3 by finding table in the back of your statistics text labeled something like "areas under normal distribution" to find the proportion related to the corresponding Z scores.