When selecting specific units you must?

When selecting specific units you must?

• A. Multiply by 100
• B. Take random number multiply by 50 then round up
• C. Add 5
• D. Subtract 2

Answer: (B)

Choosing specific units should be done using a random method that maps evenly to the total number of units. The standard approach is to generate a random fraction between 0 and 1, multiply it by the total number of units, and then round up to get a whole unit index. This ensures every unit has an equal chance of being selected. If there are 50 units, multiplying the random number by 50 and rounding up will yield a number between 1 and 50, uniformly. This randomness prevents bias in the selection. The other options don’t tie the selection to the pool size or preserve randomness, and they could bias the sample or produce invalid results.

Choosing specific units should be done using a random method that maps evenly to the total number of units. The standard approach is to generate a random fraction between 0 and 1, multiply it by the total number of units, and then round up to get a whole unit index. This ensures every unit has an equal chance of being selected. If there are 50 units, multiplying the random number by 50 and rounding up will yield a number between 1 and 50, uniformly. This randomness prevents bias in the selection. The other options don’t tie the selection to the pool size or preserve randomness, and they could bias the sample or produce invalid results.