Recent studies have indicated that nicotine may suppress the growth of bone cells and may be associated with decreased calcium absorption in humans. Since bones act as calcium stores, long periods of insufficient calcium can lead to bone loss and the risk of developing osteoporosis. Postmenopausal women are a group that is particularly at risk because of their loss of estrogen following menopause. A study was conducted to compare bone mineral density of post-menopausal women who had smoked throughout their adult lives with non-smoking postmenopausal women. It was hypothesized that the smoking group would have lower bone density than the non-smoking group. Low bone density indicates porous and fragile bones and potentially osteoporosis. Assume that bone density is approximately normally distributed. Summary statistics from the study are given in the table below.