## Elementary Statistics (12th Edition)

The sample proportion is equal to the proportion of the sample (x) divided by the sample size: $p=\frac{x}{n}=\frac{879}{945}=0.9302.$ The sample proportion of 0.9302 is not really close to the expected 0.5 and not is likely to happen. Hence there is sufficient evidence against the claim that the proportion of baby girls is 0.5.