A sociologist recorded the estimated life expectancies of women born in Center City. Use the data from women born in 1970 and 2000 to create a linear model that predicts the life expectancy, in years, (y) of a female born in a given year (x). Year
Born
Life Expectancy
(years)
1960
66.1
1970
67.6
1980
70.1
1990
71.9
2000
74.0
2010
75.9

Which equation represents this linear model?
y = 0.213x – 352.7
y = 0.213x – 358.4
y = 4.695x – 9181.6
y = 4.695x – 9322.4

Marcus and cody both leave the park at the same time, but in opposite directions. if cody travels 6 mph faster than marcus and after 4 hours they are 64 miles apart, how fast is each traveling? solve using rare times time = distance.

Barney & noblet customers can choose to purchase a membership for $25 per year members receive 10% off all store purchases 1. how much would a member pay per year if he bought $50 worth of items each year? 2. write a slope-intercept equation that expresses how much a member pays per year using x to represent his purchases per year 3. how much would a member have to spend per year to pay off his membership fee?

The management of a supermarket wants to adopt a new promotional policy of giving a free gift to every customer who spends more than a certain amount per visit at this supermarket. the expectation of the management is that after this promotional policy is advertised, the expenditures for all customers at this supermarket will be normally distributed with a mean of $95 and a standard deviation of $20. if the management wants to give free gifts to at most 10% of the customers, what should the amount be above which a customer would receive a free gift?