Question

22.32 Do chemists have more girls? Some people think that chemists are more likely than other parents to have female children. (Perhaps chemists are exposed to something in their laboratories that affects the sex of their children.) The Washington State Department of Health lists the parents’ occupations on birth certificates. Between 1980 and 1990, 555 children were born to fathers who were chemists. Of these births, 273 were girls. During this period, 48.8% of all births in Washington State were girls. Is there evidence, at a significance level of 0.05, that the proportion of girls born to chemists is higher than the state proportion? (Please provide the full hypothesis test for this problem)

Answer 1

Solution :- Ceiven that, n = 555 X = 273 d =0.05 P = x = 0.4919 n 273 555 = 48.8 % Po = 0.488 The null and alternative hypothesis Ho :P Ha: :p = 0.488 > 0.488 This is right - tailed test. Test statistic, Z = P- po Poll-po) Poch z = 0.4914 - 0.488 0.488 C1-0.488) 555 Z 0.183 The test statistic Z = 0.183

P-value = 0.4272 L = 0.05 0.4272 P-value >0.05 > 2 The P-value is greater than a fail to reject the null hypothesis. conclusion :- fail to reject Ho. There is not sufficent evidence to claim that the 48.8% greater than of all briths in Washington were girls. L= 0.05 significance level. state at