# Iam stuck with this tough question

#### mousa

##### New Member
Thanks for help me with this hursh course , please my assignment will be after less than 18 hours, so Iam looking forward toe helping me with this question:

) A measure of the physical conditioning of individuals is the volume of oxygen
consumed per minute per kilogram of body weight, VO2MAX . In a group of 87 healthy
subjects including both men and women, VO2MAX was roughly linearly related to the
duration that the subjects were capable of remaining on a treadmill. A question of
interest is whether the the relationship between VO2MAX and duration is di erent
between men and women. (These data are taken from Biostatistics: A methodology
for the health sciences by van Belle et al.) The following tables summarize the results
of fitting a multiple linear regression model with Y = VO2MAX , X1 = duration, and
X2 = gender (0=male/1=female) with an interaction term, that is, for the mo del
µY |X 1,X 2 = b0 + b1X1 + b2X2 + b3X1X2:

Coefficient SE t-statistic p-value
Intercept -1.10 2.94 -0.38 0.71
Duration 0.064 0.004 14.45 < 0.001
Gender 4.26 4.79 0.89 0.38
Gender*Duration
Interaction -0.014 0.008 -1.65 0.10

Regression Statistics Value

R² 0.850
R² a 0.845
Sy |x1, x2 3.66

(a) Is the estimated slope of the relationship between VO2MAX and duration for
females greater than or less than the slope for males? By how much?
(b) Is the di erence in slopes between males and females statistically significant (at
significance level a = 0.05)? (Indicate how you came to your conclusion.)
(c) Roughly how accurate (in terms of an standard deviation, say) do you expect
predictions of VO2MAX to be in this model? (Indicate how you arrive at this
value.)

Thanks

#### JohnM

##### TS Contributor
mousa,

Thank you very much for visiting and using our services, however, we'll need to see what you've attempted so far and any specific questions you may have.

We're happy to help, but unfortunately we're not a "homework doing" service.

JohnM