Question

A coach wants to know if baseball players who warm up before a game will score more points than those who don't warm up. He will break the team up into two groups and make sure each player gets equal time on the field. He will then count how many points each player makes during the game. What statistic should he study?

A. The mean number of points earned by each player
B. The standard deviation of the number of points earned by each player
C. The standard deviation of the number of points earned by each group
D. The mean number of points earned by each group

Answer 1

Solution:

As, Mean = $\frac{\text{Sum of all the observations}}{\text{Total number of observations}}$

Standard deviation is a number which describes or depicts relationship between mean and the number(Called Standard deviation).

So , if the difference between mean and standard deviation is large then it means data is widely spread i.e farther from mean and if Difference between mean and standard deviation is small it means data are close to mean.

So,in the given question , it is study about a group not individual players, so instead of studying mean , that gives average , if he will calculate standard deviation that is the number of points earned by each group,which will describe performance of each player as well as average of the group, that will give better description about the two groups.

Option (C) The standard deviation of the number of points earned by each group,  is true statement about the study of two groups given in this question.

Answer 2

Answer:

D. The mean number of points earned by each group

Step-by-step explanation:

THe mean number of points earned by each group is what the coach should study, and with this he will have a close idea of which group scored the most, he just needs to add up all the points scored by both teams the ones that warmed up and the ones that didn´t and they divide it by the number of players in each team, he then could have an idea of which group perfomed the best.