Acoach 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

Solution:

As, Mean =

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.

d. 24+-0.114

step-by-step explanation:

the question requires us to calculate the approximate 95% confidence interval for the mean number of ounces of ketchup per bottle in the sample given the following statistics;

sample mean = 24

standard deviation, σ = 0.4

sample size , n = 49

the confidence interval for a population mean is calculated using the formula;

sample mean ± z-score*(σ/sqrt(n))

the z-score associated with a 95% confidence interval, from the standard normal tables, is;

1.96

substituting these values into the formula;

24 ± 1.96*(0.4/7)

= 24 ± 0.112

from the alternatives given, choice d is closest to the above expression;

both graphs increase on their domain

neither graph has a y-intercept

step-by-step explanation:

the following points can be visualized easily from the graph