Question

Participants in the All American Soap Box Derby Championships in Akron, Ohio include both boys and girls (Harrow & Kereslidze, 2006). Suppose 120 of these soapbox racers are sampled and 54 of them are girls. Do these data show that only a minority of the participants are girls? Use a significance level of 0.05.

- can you draw me the graph please and explanation for the graph? Again thank you.

Answer 1

Sol:

State Null and alternatiev Hypotehsis

H0:p=0.5

H1:p<0.5

H1 is claim

alpha=.05

Test statistic

Z=p^-p/sqrt(p(1-p)/n)

p^=x/n=54/120=0.45

Z=0.45-0.5/sqrt(0.5*(1-0.5)/120

Z=-.1095

p=0.1368

p>0.05

Do not reject Null hypothesis.
Accept null hypothesis.

there is no sufficient evidence at 5% level of significance to conclude that  only a minority of the participants are girls

graph is: