Respuesta :
Answer:
a) 52.15
b) 58.53
c) 62.98
Step-by-step explanation:
We are given the following information in the question:
Mean, μ = 56
Standard Deviation, σ = 3
We are given that the distribution of x is a bell shaped distribution that is a normal distribution.
Formula:
[tex]z_{score} = \displaystyle\frac{x-\mu}{\sigma}[/tex]
a) We have to find [tex]x_0[/tex] such that
P(X < x) = 0.1
[tex]P( X < x) = P( z < \displaystyle\frac{x_0 - 56}{3})=0.1[/tex]
Calculation the value from standard normal z table, we have,
[tex]P(z < -1.282) = 0.1[/tex]
[tex]\displaystyle\frac{x_0 - 56}{3} = -1.282\\\\x_0 = 52.15[/tex]
b) We have to find [tex]x_0[/tex] such that
P(X < x) = 0.8
[tex]P( X < x) = P( z < \displaystyle\frac{x_0 - 56}{3})=0.8[/tex]
Calculation the value from standard normal z table, we have,
[tex]P(z < 0.842) = 0.8[/tex]
[tex]\displaystyle\frac{x_0 - 56}{3} = 0.842\\\\x_0 = 58.53[/tex]
c) We have to find [tex]x_0[/tex] such that
P(X > x) = 0.01
[tex]P( X > x) = P( z > \displaystyle\frac{x - 56}{3})=0.01[/tex]
[tex]= 1 -P( z \leq \displaystyle\frac{x - 56}{3})=0.01 [/tex]
[tex]=P( z \leq \displaystyle\frac{x - 56}{3})=0.99 [/tex]
Calculation the value from standard normal z table, we have,
[tex]P(z < 2.326) = 0.99[/tex]
[tex]\displaystyle\frac{x_0 - 56}{3} = 2.326\\\\x_0 = 62.98[/tex]
