Identify the type of observational study (cross-sectional, retrospective, or prospective) described below. a research company uses a device to record the viewing habits of about 2500 households, and the data collected over the past 2 years will be used to determine whether the proportion of households tuned to a particular children's program increased. which type of observational study is described in the problem statement?

a. a prospective study
b. a retrospective study
c. a cross-sectional study

B

Step-by-step explanation:

The retrospective or historic cohort story, is a longitudinal cohort story that considers a particular set of individuals that share the same exposure factor to ascertain its influence in the developments of an occurrence, which are compared with the other set or cohort which were not exposed to the same factors.

Retrospective studies have existed about the same time as prospective studies, hence their names.

4/6 = 2/3

so it should take 3/3 hours per man. so 9 hours is the answer 3*3 =9

step-by-step explanation:

irrational, cannot