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Men versus women The National Assessment of Educational Progress (NAEP)

Young Adult Literacy Assessment Survey interviewed separate random samples of840

men and 1077women aged 21to 25years.

The mean and standard deviation of scores on the NAEP’s test of quantitative skills were x1=272.40and s1=59.2for the men in the sample. For the women, the results were x ̄2=274.73and s2=57.5.

a. Construct and interpret a 90% confidence interval for the difference in mean score for

male and female young adults.

b. Based only on the interval from part (a), is there convincing evidence of a difference

in mean score for male and female young adults?

Short Answer

Expert verified

(a)90% confidence interval for the difference in mean score for

male and female young adults is in between -1.645to+1.645

(b)No,there is no convincing evidence of a difference

in mean score for male and female young adults.

Step by step solution

01

Part (a) Step 1:Given Information

We have been given that,

For men:

Number of men =840

Mean score of men =272.40

Standard Deviation of men =59.2

For women:

Number of women =1077

Mean score of women =274.73

Standard Deviation of women =57.5

σ=0.10

02

Part (a) Step 2:Explanation

X1=Observed mean in first sample

X2=Observed mean in second sample

μ1=mean of first population

μ2=proportion in second population

Observed value of difference in proportions=X1-X2

Expected value of difference in proportions=μ1-μ2=0

Standard Deviation= localid="1654275753578" σ12n1+σ22n2

z=Observedvalue-ExpectedvalueStandardDeviation

localid="1654275760409" z=X1-X2-0σ12n1+σ22n2

z=272.40-274.73-02.68

z=-0.86

So, the calculated value =-0.86

The tabulated value at 90% confidence level =±1.645

03

Part (b) Step 1:Given Information

We have to find ,

whether there is a difference in mean score for male and female young adults.

04

Part (b) Step 2:Explanation

Null hypotheses:There is no difference in mean score for male and female young adults.

Alternative hypotheses:There is difference in mean score for male and female young adults.

Calculated value of z =-0.86

Tabulated value of z =±1.645

Since,Zcal<Ztab

Null hypotheses is not rejected.

Conclusion:There is no difference in mean score for male and female young adults.

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