Astationery store wants to estimate the mean retail value of greeting cards that it has in its inventory. a random sample of 100 greeting cards indicates a mean value of $2.55 and a standard deviation of $0.44.a. asumming a normal distribution, construct a 95% confidence interval estimate of the mean value of all greeting cards in the store's inventory. b. suppose there were 2,500 greeting cards in the store's inventory. how are the results in (a) useful in assisting the store owner to estimate the total value of her inventory?

Rectangle leg this 11feet and perimeter of 38feet what is the width of the rectangle in feet

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?

Carl's candies has determined that a candy bar measuring 3 inches long has a z-score of +1 and a candy bar measuring 3.75 inches long has a z-score of +2. what is the standard deviation of the length of candy bars produced at carl's candies?