Hormone replacement therapy (HRT) is thought to increase the risk of breast cancer. The accompanying data on x percent of women using HRT and y breast cancer incidence (cases per 100,000 women) for a region in Germany for 5 years appeared in the paper *Decline in Breast Cancer Incidence after Decrease in Utilization of Hormone Replacement Therapy." The authors of the paper used a simple linear regression model to describe the relationship between HRT use and breast cancer incidence. HRT Use Breast Cancer Incidence 46.30 103.30 40.60 105.00 39.50 100.00 36.60 93.80 30.00 83.50 (a) What is the equation of the estimated regression line? (Round your numerical values to four decimal places.) 9= (b) What is the estimated average change in breast cancer incidence (in cases per 100,000 women) associated with a 1 percentage point increase in HRT use? (Round your answer to four decimal places.) cases per 100,000 women (c) What breast cancer incidence (in cases per 100,000 women) would be predicted in a year when HRT use was 33%? (Round your answer to three decimal places.) cases per 100,000 women (d) Should this regression model be used to predict breast cancer incidence for a year when HRT use was 23%? Explain. Yes, this is advisable as 23 is outside of the range of the x-values in the original data set. No, this is not advisable as 23 is outside of the range of the x-values in the original data set. No, this is not advisable as 23 is outside of the range of the y-values in the original data set. ◇ Yes, this is advisable as 23 is outside of the range of the y-values in the original data set.