Question

. A new method to increase the probability of conceiving a pregnancy of particular gender was used on 425 women who ended up pregnant. For these females, the procedure was used to increase the likelihood of conceiving a female baby. Of these 425 pregnancies, 68% were female babies. Using the .10 level of significance, does this provide statistically significant evidence that the procedure improves the chances of having a particular gender? find State hypotheses and test stat, p value and decision

Answer 1

given data are sample n =425

sample proportion is =68% = 0.68

population proportion p=50%=0.50 (assume)

null hypothesis H0 :- p=0.50

alternative hypothesis Ha :- p>0.50

= level of significance =0.10

test statistic: - z=

z=(0.68-0.50)/

= 0.18/0.02425

= 7.4216

p- value: - in 1 tail from z table

p (z>7.4216)0.0000

decision: - pcal <p

so reject the null hypothesis H0

at 0.10 level their is statistically significant evidence to support the claim that the procedure improves the chances of having a particular baby