Consider a case where we do a simple linear regression of the relationship between daily coffee intake (predictor, a quantitative variable expressed in number of 8oz cups per day) and sleep quantity (outcome, a quantitative variable measured in hours slept per night). What kind of measure of effects does a simple regression give us?
a. Unadjusted effect of daily coffee intake on sleep quantity, measured in the amount of change in hours slept per night we expect for every unit increase in cups of coffee consumed per day
b. Adjusted effect of daily coffee intake on sleep quantity, measured in the amount of change in hours slept per night we expect for every unit increase in cups of coffee consumed per day
c. Unadjusted effect of daily coffee intake on sleep quantity, measured in the odds of having a low number of hours slept per night for high coffee intake subjects compared to low coffee intake subjects
d. Adjusted effect of daily coffee intake on sleep quantity, measured in the odds of having low hours slept per night for high coffee intake subjects compared to low coffee intake subjects