z). By symmetry, a/2 = P(Z > z).-The endpoints for a (1 - a)100%, confidence interval for u, if o is known and either the population is normal or n2 30, are given byx ± 70z where the value of z is...

Extracted text: For a data set obtained from a sample of size n = 100 with x = 46.25, it is known that o = 4.8. (a) What is the point estimate of µ? (b) Find z score corresponding to a 95% confidence level, za/2. Recall that (1- a)100% = 95%. (c) Constructa 95% confidence interval for u. (d) What is the margin of error in part (c)? Recall the following definitions from section 8.2-3 of the text. The confidence level is denoted by (1 – a)100%, where a is called the significance level. a = P(|Z| > z). By symmetry, a/2 = P(Z > z). - The endpoints for a (1 - a)100%, confidence interval for u, if o is known and either the population is normal or n2 30, are given by x ± 70z where the value of z is obtained from the standard normal distribution (Table IV in Appendix C or by calculator) and is the standard deviation of X. Vn O = The quantity zoz is called the Margin of Error and is denoted by E. To obtain z from a graphing calculator we use the formula z = invNorm(1 – a/2, µ, o) where µ is the mean and o is the standard - deviation of the normal distribution. For standard normal distribution u = 0 and o = 1. Recall that in general z = invNorm("area to left of z", µ, o)