# Question: We are often interested in finding the value of z

We are often interested in finding the value of z that bounds a given area in the left-hand tail of the normal distribution, as shown in the accompanying figure. The notation z(a) represents the value of z such that P(z > z(a)) = a.

Find the following:

a. z(0.98)

b. z(0.80)

c. z(0.70)

Find the following:

a. z(0.98)

b. z(0.80)

c. z(0.70)

## Answer to relevant Questions

Use Table 4A, Appendix B, and the symmetry property of normal distributions to find the following values of z. a. z(0.05) b. z(0.01) c. z(0.025) d. z(0.975) e. z(0.98) a. Find the area under the normal curve for z between z(0.95) and z(0.025). b. Find z(0.025) - z(0.95). Find the normal approximation for the binomial probability P(x = 6), where n = 12 and p = 0.6. Compare this to the value of P(x = 6) obtained from Table 2. In reference to Applied Example 7. 3 on page 316: a. Explain why the numerical values on this table do not form a sampling distribution. b. Explain how this repeated gathering of data differs from the idea of repeated ...a. What numerical statistics would you use to describe the “ages” sample data in Exercise 7.1? Calculate those statistics. According to the 2000 census (2010 census is not complete), 275 million Americans have a mean age ...Post your question