The 2014 S. A.T. exam administered in Clark County had a mean of 400 and a standard deviation of 125. A total
of 10,000 Clark County High School seniors took this exam in 2014. Draw a normal curve and label the mean,
and the scores that represent up to 2 standard deviations above and below this mean. What percent of student scored above 525? what percent of student scored at least 275? What percent of student scored between 275 and 400?

Data from 2005 for various age groups show that for each $100 increase in the median weekly income for whites, the median weekly income of blacks increases by $105. also, for workers of ages 25 to 54 the median weekly income for whites was $676 and for blacks was $527. (a) let w represent the median weekly income for whites and b the median weekly income for blacks, and write the equation of the line that gives b as a linear function of w. b = (b) when the median weekly income for whites is $760, what does the equation in (a) predict for the median weekly income for blacks?