The market research director for Dotty’s Department Store wants to study women’s spending on cosmetics. A survey of the store’s customers is designed in order to estimate the proportion of women who purchase their

cosmetics primarily from Dotty’s Department Store and

the mean yearly amount that women spend on cosmetics.

A previous survey found that the standard deviation of the

amount women spend on cosmetics in a year is approximately $18.

a. What sample size is needed to have 99% confidence of estimating the population mean amount spent to within

b. How many of the store’s credit card holders need to be

selected to have 90% confidence of estimating the population proportion to within +-0.045?

Your dormitory, griffingate, has appointed you central banker of its economy, which deals in the currency of wizcoins. assume that the velocity of wizcoins in griffingate is constant at 10,000 transactions per year. right now, real gdp is 1,000 wizcoins, and there are 2,000 wizcoins in existence.

The monthly demand equation for an electric utility company is estimated to be p equals 60 minus left parenthesis 10 superscript negative 5 baseline right parenthesis x, where p is measured in dollars and x is measured in thousands of killowatt-hours. the utility has fixed costs of $3 comma 000 comma 000 per month and variable costs of $32 per 1000 kilowatt-hours of electricity generated, so the cost function is upper c left parenthesis x right parenthesis equals 3 times 10 superscript 6 baseline plus 32 x. (a) find the value of x and the corresponding price for 1000 kilowatt-hours that maximize the utility's profit. (b) suppose that the rising fuel costs increase the utility's variable costs from $32 to $38, so its new cost function is upper c 1 left parenthesis x right parenthesis equals 3 times 10 superscript 6 baseline plus 38 x. should the utility pass all this increase of $6 per thousand kilowatt-hours on to the consumers?

Atariff on avocadoes the price of avocadoes, consumers' surplus for avocado buyers, producers' surplus of avocado growers and tariff revenue. because the loss to is more than the gain to there is a net loss to society.raises; decreases; increases; generates; consumers; producers and government raises; increases; decreases; does not generate; producers and government; consumers lowers; increases; decreases; does not generate; producers and government; consumers raises; increases; decreases; generates; producers; consumers and government