SAT Question 708590d7: Distributions, Center & Spread answer and explanation with Desmos solution

Choice D is correct. The mean of a data set is found by dividing the sum of the values in the data set by the number of values in the data set. Therefore, the mean of data set A is $\frac{1+2+3+4+5+6+7}{7}=\frac{28}{7}$, or $4$. The mean of data set B is $\frac{1+1+2+2+3+3+4}{7}=\frac{16}{7}$, or approximately $2.2857$. Therefore, the mean of data set A is greater than the mean of data set B.

Alternate approach: Data set A and data set B are both ordered from least to greatest value. Besides the first value in each data set, which is $1$, each value in ordered data set B is less than the respective value in ordered data set A. Therefore, conceptually, the mean of data set A must be greater than the mean of data set B.