Sampling Methods Quiz

Probability and Statistics

• The probability that X gets at least 10 marks is 0.9997.
• On average, 5% of items supplied by manufacturer X are defective.

Binomial Distribution

• The probability that 2 items are defective in a batch of 10 items is 0.075.

Poisson Distribution

• A car distributor in City Y experiences an average of 2.5 car sales daily.
• The probability that on a randomly selected day, they will sell 5 cars is 0.0668.
• The probability that on a randomly selected day, they will sell no cars is 0.082.
• The probability that on a randomly selected day, they will sell at most 2 cars is 0.544.
• The probability that on a randomly selected day, they will sell exactly one car is 0.205.

Survey Research

• One should not go for sampling because none of the above reasons (less costly, comfortable with the sample, destructive research process) are correct.
• Stratified random sampling is a method of selecting a sample in which the population is first divided into strata, and then random samples are drawn from each stratum.

Sampling Distribution

• If the true proportion of customers who are below 20 years is P=0.35, the probability that a sample size of 100 yields a sample proportion between 0.3 to 0.4 is 0.706.

Binomial Distribution (Coin Toss)

• The probability of getting 12 heads in 20 attempts from a fair coin is 0.120.

Multiple-Choice Questions

• A question paper contains 90 multiple-choice questions, each correct answer carries 1 mark, and there are 4 alternative answers (A, B, C, or D), of which only one is correct.
• Mr. X answers these questions randomly (i.e., without preparation).