State the estimated distribution of P.Construct a 92%Confidence Interval for the true proportion of girls in the ages 8to12beginning ice-skating classes at the Ice Chalet.

Short Answer

Expert verified

The result is 92%Confidence Interval for the true proportion of girls in the ages 8to 12beginning iceskating classes at the lce Chalet is 0.7217<p<0.8783.

Step by step solution

01

Given 

p^=x/nis the point estimate of p, where x is the number of favour able events and n is the total number of events.

02

Explanation part 1

Given that there were 64girls and 16boys in that class.

So , x=64andn=64+16=80.

So that, p^=64/80=0.8.

For a sample size of 80, the mean of the sampling distribution of the sample proportion is,

μp^=p=0.8.

The distribution of p^is approximately normal with mean 0.8and standard deviation of 0.044721359.

For the population proportion, pthe 100(1-α)%confidence interval is:

p^±zα2p^(1-p^)n

the sample size is n, and for level of significance αthe standard normal distribution critical value is zα2.

Considerp, the proportion of students accepted into law school from the general population, and n, the sample size.

The confidence level is92%.

The level of significance is α=1-0.92=0.08. Hence, α/2=0.04.

03

Explanation part 2

If of the observations must lie within an interval, the remaining must lie outside the interval.

Due to symmetry, of the population will be above the top limit, while the remaining will be below the lower limit of the interval.

Thus, the upper limit of the interval is such that, lie below it.

As a result,

The confidence interval is,

Cl=p^±za2p^(1p^)n=0.8±(1.751)(0.8)(10.8)80=(0.8±(1.751)(0.044721359))=(0.8±0.0783071)(0.7217,0.8783)

the result of confidence Interval for the true proportion of girls in the ages to beginning iceskating classes at the lce Chalet is.

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