Answer: cross-sectional study
Step-by-step explanation:
- A cross-sectional study is a kind of research study in which a researcher collects the data from many different persons at a single point in time.
- In this study researcher observes the variables without influencing them.
Here, A research company uses a device to record the viewing habits of about 2500 households (that includes different persons such as adults , children and seniors )
The data collected today(at a single point in time).
If it is used to determine the proportion of households tuned to a particular children's children's program.
The type of observational study is described in the problem statement : "cross-sectional"
Answer and Explanation:
Odds ratio is the odds that an outcome would happen given a level of exposure in comparison to the occurrence of that outcome without exposure. Odds ratio is calculated by dividing odds of event occurring with exposure(the first group) by odds of event(usually disease) occurring without exposure. Odds is different from probability(denoted p/1-p). While probability is the number of favorable events divided by total number of events, odds is number of favorable events/number of unfavorable events.
Relative risk, also measuring relationship between exposure and outcome, is the ratio of the probability that an outcome would occur without exposure and probability that an outcome would occur with exposure.
The answer and the process is shown in the following picture
The answer is B because 4 X 7 is 28 so 9 times 7 is 63
