Final answer:
The given information does not provide enough data to calculate the p-value for the two-sample t-test.
Step-by-step explanation:
The p-value for the two-sample t-test comparing mean birthweight for babies whose mothers smoke with those whose mothers do not smoke can be obtained from the given information. However, the provided information does not directly give the necessary data for calculating the p-value. In order to calculate the p-value, we would need data on the mean birthweight of babies in both groups (smoking and non-smoking mothers) along with their respective sample sizes, standard deviations, and the significance level of the test.