The population standard deviation for the age of Foothill College students is 15 years. If we want to be 95% confident that the sample mean age is within 2 years of the true population mean age of Foothill College students , how many randomly selected Foothill College students must be surveyed?
From the problem, we know that σ = 15 and EBM = 2
z = z.025 = 1.96, becuase the confidence level is 95%.
n=\frac{z^{^{2}}\sigma ^{2}}{EBM^{2}}=\frac{1.96^{^{2}}15 ^{2}}{2^{2}}=216.09
using the sample size equation.
Use n = 217: Always round the answer UP to the next higher integer to ensure that the sample size is large enough.
Therefore, 217 Foothill College students should be surveyed in order to be 95% confident that we are within 2 years of the true population mean age of Foothill College students.

U.s. internet advertising revenue grew at the rate of r(t) = 0.82t + 1.14 (0 ≤ t ≤ 4) billion dollars/year between 2002 (t = 0) and 2006 (t = 4). the advertising revenue in 2002 was $5.9 billion.† (a) find an expression f(t) giving the advertising revenue in year t.

Your uncle is considering investing in a new company that will produce high quality stereo speakers. the sales price would be set at 1.5 times the variable cost per unit; the variable cost per unit is estimated to be $75.00; and fixed costs are estimated at $1,200,000. what sales volume would be required to break even, i.e., to have ebit = zero?

Profits from using currency options and futures.on july 2, the two-month futures rate of the mexican peso contained a 2 percent discount (unannualized). there was a call option on pesos with an exercise price that was equal to the spot rate. there was also a put option on pesos with an exercise price equal to the spot rate. the premium on each of these options was 3 percent of the spot rate at that time. on september 2, the option expired. go to the oanda.com website (or any site that has foreign exchange rate quotations) and determine the direct quote of the mexican peso. you exercised the option on this date if it was feasible to do so. a. what was your net profit per unit if you had purchased the call option? b. what was your net profit per unit if you had purchased the put option? c. what was your net profit per unit if you had purchased a futures contract on july 2 that had a settlement date of september 2? d. what was your net profit per unit if you sold a futures contract on july 2 that had a settlement date of september 2