Question

a.) For a standard normal curve, find the area between z = 0.28 and z = 1.95. (Use 4 decimal places.)

b.) Find the positive z value such that 89% of the standard normal curve lies between –z and z. (Use 2 decimal places.)

c.) Given a normal distribution with population standard deviation of 21 and a mean of μ = 29. If a random sample of size 62 is drawn, find P(29 ≤ x ≤ 31).
Round to three decimal places.

d.) If we want to estimate p, the population proportion of likely voters who believe the state of the economy to be the most urgent national concern, with 90% confidence and a margin of error no greater than 2%, how many likely voters need to be surveyed? Assume that you have no idea of the value of p.

-1024

-1692    

-4096

-6765

Answer 1