Answer to Question #121614 in Statistics and Probability for Leah Li

Question

Using least-squares regression, the relationship between time spent gaming and phys. ed. grade is modelled by: (grade) = -1.8568*(hours gaming) + 95.728.

a) According to the model, a student who played video games 7 hours per week would have a grade of ___ % (round to the nearest tenth of a decimal place)

b) According to the model, a student who achieved a grade of 90% would spend ___ hours gaming per week (round to the nearest hour)

c) Describe the most plausible causal relationship between the number of hours spent gaming and a student's grade in physical education (e.g. accidental, common cause, etc.)

Answer 1

a) hours gaming is 7 hours

Grade =-1.8568*(7)+95.728

=82.7%

b) grade is 90%

90=-1.8568*(hours gaming )+95.728

Hours gaming =3 hrs

c) The most plausible causal relationship between number of hours spent gaming and grade is the age of the student. Adolescents spent less time playing compared to the younger children.