Suppose it is known that the “average” cholesterol level in children is 175mg/dL
ID: 3130317 • Letter: S
Question
Suppose it is known that the “average” cholesterol level in children is 175mg/dL. A group of men who have died from heart disease within the past year is identified, and the cholesterol levels of their offspring are measured. One wishes to test the hypothesis that these children have greater cholesterol levels than the average child.
A sample of 81 children from fathers with heart disease was selected. The average cholesterol level for these children was 178 with a standard deviation of 8.9. At the =.05 level of significance, what is your conclusion?
State researchers hypothesis, calculate test statistic and p-value, state decision (whether or not H0 is rejected), Conclusion, if H0 is rejected construct a confidence interval, and what type of error is possible?
Explanation / Answer
Set Up Hypothesis
Null, H0: U=175
Alternate, children have greater cholesterol levels than the average child H1: U>175
Test Statistic
Population Mean(U)=175
Sample X(Mean)=178
Standard Deviation(S.D)=8.9
Number (n)=81
we use Test Statistic (t) = x-U/(s.d/Sqrt(n))
to =178-175/(8.9/Sqrt(81))
to =3.034
| to | =3.034
Critical Value
The Value of |t | with n-1 = 80 d.f is 1.664
We got |to| =3.034 & | t | =1.664
Make Decision
Hence Value of | to | > | t | and Here we Reject Ho
P-Value :Right Tail - Ha : ( P > 3.0337 ) = 0.00163
Hence Value of P0.05 > 0.00163,Here we Reject Ho
We have evidence that children have greater cholesterol levels than the average child