Question

A Little League baseball coach wants to know if his team is representative of other teams in scoring runs. Nationally, the average number of runs scored by a Little League team in a game is 5.7. He chooses five games at random and finds the mean number of runs scored is 7.4 with a sample standard deviation of 2.88.
Required:
Is it likely that his team's scores is different than the national average?

Answer 1

Answer:

That result implies that t(s) is in the acceptance region for H₀ then we accept H₀, there is not statistics difference between the LL team and the national average

Step-by-step explanation:

The National average number of runs scored by a LL team is

μ   =  5.7

Sample Information:

size sample   n = 5

sample average   x  =  7.4

sample standard deviation    s  =  2.88

Is required to investigate if  that sample average is statistically different from the National average

We will do a test with 95 % of confidence Interval that means

significance level α = 5 %   or α = 0.05.

The sample size is 5 then even when we assume normal distribution the sample size indicates that we need to use t-student distribution. Furthermore, as the question is if the sample average is different from the national the test will be a two-tail test.

Then  α = 0.05    α/2  =  0.025

df  =  n  -  1     df  =  5  -  1     df  =  4

Then from t-student table we get  t(c)  =  2.132

Hypothesis test:

Null Hypothesis                                  H₀              x  =  μ

Alternative Hypothesis                      Hₐ              x  ≠  μ

To calculate t (s)

t(s)  = ( x  -   μ ) / s/√n

t(s)  = ( 7.4  -  5.7  )* 2.24 / 2.88

t(s)  =  1.7* 2.24 / 2.88

t(s)  = 1.32

Comparing  t(s)  and  t(c)

1.32 < 2.132

That result implies that t(s) is in the acceptance region for H₀ then we accept H₀, there is not statistics difference between the LL team and the national average