The inside diameter of a randomly selected piston ring is a normally distributed random variable with mean 12 cm and standard deviation 0.04 cm. (a) What is the diameter that is exceeded by only 5% of the piston rings

Respuesta :

Answer:

[tex]x=12.07[/tex]

Step-by-step explanation:

From the question we are told that:

Mean [tex]\=x =12cm[/tex]

Standard deviation [tex]\sigma=0.04[/tex]

Significance level [tex]\alpha=5\%=0.05[/tex]

Therefore

Confidence level [tex]95\%=0.95[/tex]

From table [tex]P(z<1.645)=0.95[/tex]

Generally the equation for Z-score is mathematically given by

[tex]z=\frac{x-\mu}{\sigma}[/tex]

[tex]x=z\sigma+\mu[/tex]

[tex]x=1.645*0.04+12[/tex]

[tex]x=12.07[/tex]