Why are sample surveys preferred in statistics?

They provide reliable information at lower cost and shorter time

The correct answer is option 3: They provide reliable information at lower cost and shorter time

Sample surveys are preferred because they can provide reasonably reliable and accurate information at a lower cost and shorter time compared to surveying the entire population.

Here's why the other options are not the main reasons for preferring sample surveys:

A) They provide more accurate information than census surveys: While a well-designed sample survey can be very accurate, in general, censuses are considered more accurate because they involve everyone.
B) They are more expensive and time-consuming: This is the opposite of the main advantage. Sample surveys are cheaper and faster than censuses.
D) They eliminate the need for data analysis: Data analysis is still crucial in sample surveys to interpret the information gathered from the sample and draw conclusions about the larger population.