Question

QUESTION 13 4 pc The lifetime of salmon flies is normally distributed with a mean of 60 days and a standard deviation of 20 days, Find the value xo such that 6.3% of salmon flies live less than xo days. QUESTION 14 4 poi Find P(-1.96<=Z <=2.58)? QUESTION 15 4 poir Determine the value of Zo which satisfies Plz < 20 ) = 0.1.

Answer 1

Solution:

13.

Using standard normal table,

P(Z < z) = 6.3%

P(Z < -1.53) = 0.063

z = -1.53

Using z-score formula,

x = z * $\sigma$ + $\mu$

x = -1.53 * 20 + 60 = 29.4

value = 29.4days

14.

Using standard normal table,

P(-1.96 < z < 2.58)

= P(z < 2.58) - P(z < -1.96)

= 0.9951 - 0.025

= 0.9701

P(-1.96 < = z < = 2.58) = 0.9701

15.

Using standard normal table,

P(Z < z_o) = 0.1

P(Z < -1.28) = 0.1

z_o = -1.28

16.

Using standard normal table,

P(z > 1.48) = 1 - P(z < 1.48) = 1 - 0.9306 = 0.0694