Posted by Sue on Sunday, May 26, 2013 at 10:05am.
The accompanying data show the number of hours, x, studied for an exam and the grade received, y (y is measured in tens; that is, y = 8 means that the grade, rounded to the nearest 10 points, is 80).
x 2 3 3 4 5 5 5 6 6 6 7 7 7 7 8
y 5 5 6 5 6 7 8 6 9 8 7 9 10 8 9
Maple Generated Plot
(a) Use the given scatter diagram to estimate r for the sample data on the number of hours studied and the exam grade.
(b) Calculate r. (Give your answer correct to two decimal places.)
- Statistics - MathMate, Sunday, May 26, 2013 at 10:07am
Are you expected to use Maple to do this exercise?
What are the answers?
- Statistics - Sue, Sunday, May 26, 2013 at 10:12am
There is a diagram but I wasn't sure what to call it so I did not know how to look it up. I cant find anything in this chapter on how to calculate r? Or Maple.
- Statistics - MathMate, Sunday, May 26, 2013 at 10:30am
Maple can certainly find r, called the coefficient of correlation.
The coefficient of correlation, r, for a population can be calculated using the following formula (one of the different forms):
r=(nΣxy-(Σx)( Σy)) / √[(nΣx²-(Σx)²)(nΣy²-(Σy)²)]
n=number of observations in the population.
The formula looks scary, but if you form a table and calculate the summations systematically, it would not take more than a few minutes.
For a check, r approximately equals 0.8.
Answer This Question
More Related Questions
- eced - A correlatibas .82 was found betweenen number of hours studied and final ...
- statistics - Can someone work this out for me, so I can use as an example to do ...
- statistics - The data below are the final exam scores of 10 randomly selected ...
- Statistics - Does studying for an exam pay off? The number of hours studied, x, ...
- statistics - Does studying for an exam pay off? The number of hours studied, x, ...
- Statistics 1 - Professor White asked his students to put the number of hours ...
- statistics - 12. A statistics student received a grade of 85 on a statistics ...
- statistics - An 8th grade history teached studied the statistics for her mid-...
- statistics - 2. The grades on a statistics midterm exam were normally ...
- msth - Professor White asked his students to put the number of hours each ...