State the modulus and argument of each complex number. explain how you know.
a. 4 + 0i
b. −2 + 2i

Find the amount in a continuously compounded account for the given condition. principal: $1000, annual interest rate: 4.8%, time: 2 yr

An elevator travels 310 feet in 10 seconds. at that speed, how far can't his elevator travel in 12 seconds?

Arandom sample of n = 25 observations is taken from a n(µ, σ ) population. a 95% confidence interval for µ was calculated to be (42.16, 57.84). the researcher feels that this interval is too wide. you want to reduce the interval to a width at most 12 units. a) for a confidence level of 95%, calculate the smallest sample size needed. b) for a sample size fixed at n = 25, calculate the largest confidence level 100(1 − α)% needed.