The random variable X is normally distributed. Also, it is known that P(X > 141)
ID: 3321436 • Letter: T
Question
The random variable X is normally distributed. Also, it is known that P(X > 141) = 0.09. Use Table 1.
a. Find the population mean if the population standard deviation = 12. (Round "z" value and final answer to 2 decimal places.)
b. Find the population mean if the population standard deviation = 27. (Round "z" value and final answer to 2 decimal places.)
c. Find the population standard deviation if the population mean = 120. (Round "z" value to 2 decimal places and final answer to 2 decimal places.)
d. Find the population standard deviation if the population mean = 113. (Round "z" value to 2 decimal places and final answer to 2 decimal places.)
Explanation / Answer
solution=
given
P(X > 141) = 0.09
using z score table( 1 - 0.535856 = 0.464144
a) Find the population mean if the population standard deviation = 12
P(X > 141)= 0.4641
141 - / 12 = 0.4641
141 - = 12 * 0.4641
= 141 - 5.5692
= 135.43
b. Find the population mean if the population standard deviation = 27.
141 - / 27 = 0.4641
141 - = 27 * 0.4641
= 141 - 12.5307
= 128.47
c. Find the population standard deviation if the population mean = 120
141 - 120 / = 0.4641
=141 - 120 / 0.4641
=45.25
d. Find the population standard deviation if the population mean = 113?
141 - 113 / = 0.4641
=141 - 113 / 0.4641
= 60.33