Question

Hours Worked
Overall Grade
A counselor asked college students who had jobs how many hours they worked each week. The counselor then compared the number of hour each student worked and the student's overall grade average. The table shows the data.



1. What is the value of the correlation coefficient ("r"
r-value)? Do not round, just type what your calculator state

Answer 1

I don't see the table of hours and grades in your message. Please paste the data (or a clear picture of the table) and I can compute r for you.

If you want to get r yourself, here are quick instructions for common tools:

- TI-83/84:
1. STAT → EDIT and enter hours in L1 and grades in L2.
2. Turn on diagnostics: 2nd → 0 (CATALOG) → scroll to DiagnosticOn → ENTER → ENTER.
3. STAT → CALC → 4:LinReg(ax+b) → ENTER. The calculator displays a, b, r, and r^2 (type exactly what the calculator shows).

- TI-89:
Use the Stat/List Editor to enter lists, then Statistics → Stat Calculations → Linear Regression to get r.

- Excel / Google Sheets:
=CORREL(range_of_hours, range_of_grades)

- Manual formula (Pearson correlation):
r = [n·Σ(xy) − Σx·Σy] / sqrt([n·Σ(x^2) − (Σx)^2]·[n·Σ(y^2) − (Σy)^2])

Send the data and I’ll compute (or verify) the exact r your calculator would show.