A study of 375 women who lived in pre-industrial Finland using Finnish church records from 1640 to 1870 found that there was roughly a linear relationship between y=lifelength (in years) and x= number of sons the woman had, with a slope estimate of -.65 (se=.29)

1. Interpret the sign of the slope. Is the effect of having more boys good or bad?

2. Researchers are wondering whether lifelength is independent of number of sons. Can you help them answer this question? If so, do so by conducting a hypothesis test.

3. Give a 95% confidence interval for the true slope. Interpret. Is it plausible that the effect is relatively weak, with true slope near 0?