Question

Recipes for the same type of cookies can vary in terms of ingredients and baking times. From a collection of chocolate chip cookie recipes, a baker randomly selected 5 recipes. From a collection of oatmeal raisin cookie recipes, the baker randomly selected 4 recipes. The mean baking times, in minutes, for each sample were recorded as x¯Cx¯C and x¯Ox¯O, respectively.

What is the correct unit of measure for the standard deviation of the sampling distribution of x¯C−x¯Ox¯C−x¯O?

• Minutes

  A

• Minutes squared

  B

• Recipes

  C

• Number of Raisins

  D

• Number of Chocolate Chips

• E

Answer 1

The mean baking times, for recipes of chocolate cookies is in minutes

The mean baking times, for recipes of oatmeal cookies is in minutes

is the difference between the mean baking times of the two types of recipes

Thus is also in minutes

Unit of measurement of sampling distribution of is minutes

Standard deviation is the deviation of the data from the mean

Hence, unit of measurement of standard deviation is same as that of the variable in the distribution

Hence, unit of measure for the standard deviation of the sampling distribution of is Minutes