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Children make choices Refer to Exercise 15.

a. Explain why the sample results give some evidence for the alternative hypothesis.

b. Calculate the standardized test statistic and P-value.

c. What conclusion would you make?

Short Answer

Expert verified

a. The sample proportion of 4to 5year old who can sort correctly is smaller than the the sample proportion of 6to 7year old who can sort correctly.

b. The Pvalue is 0.0003and test static value is -3.45.

c. Conclusion is that there is evidence that there is a greater proportion of 6to 7year old who can sort correctly than the proportion of 4to 5year old who can sort correctly.

Step by step solution

01

Given Information

It is given that researchers want to know that if a greater proportion of 6to 7year old can sort correctly than 4to 5year old or not.

x1=10

x2=28

n1=50

n2=53

02

The reason that sample results give evidence for alternative hypothesis

Claim is population is greater for 6-7years old.

The hypothesis is:

Null: H0:p1=p2

Alternative: Ha:p1<p2

p1is the proportion of 4-5year old who can sort correctly.

p2is the proportion of 6-7year old who can sort correctly.

Sample proportion is p^1=x1n1=1050=0.20

p^2=x2n2=2853=0.5283

p1<p2, there is some evidence for alternative hypothesis.

03

Test Statistics and P value.

From above part, p^1=0.20and p^2==0.5283

and p^p=x1+x2n1+n2=10+2850+53=38103=0.3689

Value of test statistics is:

z=p^1-p^2-p1-p2p^p1-p^p1n1+1n2

=0.20-0.5283-00.3689(1-0.3689)150+153

-3.45

Thus probability is P=P(Z<-3.45)=0.0003

04

Conclusion

From above:

H0:p1=p2

Ha:p1<p2

As Pvalue is less than significance level P<0.05RejectH0
There is evidence present that there is greater proportion of6-7years old who can sort correctly than proportion of4-5years old who can sort correctly.

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