Question

The hypothesis that high trichome numbers provide resistance to herbivores in a population of Brassica rapa was tested. One of the first steps of this investigation was to get a separate population exhibiting a higher number of trichomes from a wild population.
This wild population is represented as Generation 1 in the table below. Plants in the top 10 percentile of trichome number were only crossed with each other. The offspring of this cross are represented in generation 2 in the table below.

The number of trichomes found on 15 plants in two generations of Brassica rapa after a round of selection.

Generation 1	Generation 2
0, 5, 0, 11, 8, 0, 0, 9, 12, 0, 22, 0, 3, 4, 9	21, 14, 7, 27, 1, 0, 19, 23, 41, 0, 3, 15, 14, 20, 13

What is an appropriate step to take to reduce the standard error of the mean (SEM)?

• A. When collecting data, only use every other plant to count trichomes.
• B. Only count those plants in Generation 1 with zero trichomes present and only count those in Generation 2 that have over 10 trichomes present.
• C. Increase the sample size for each generation.
• D. Decrease the sample size for each generation.

Answer 1

The correct option is C Increase the sample size for each generation.

The standard error of the mean, also called the standard deviation of the mean, is a method used to estimate the standard deviation of a sampling distribution.

The sample size is a count the of individual samples or observations in any statistical setting, such as a scientific experiment or a public opinion survey When the sample size is large the results are reliable and accurate while with small sample sizing the results vary and are not accurate.

So, the correct answer is 'Increase the sample size for each generation'