Question

2 pts Question 1 -78 and - 8 Let X - a score on the final exam. X-N78,8).where Then, find Pix > 88) (round to 4 decimal places) Example on page 369 Wk6Hw_zProb5

Answer 1

Refer to ;

Cumulative Area Under the Standard Normal Distribution Table

D=(X-Mean)/(Standard Deviation)

Mean =78

Standard Deviation =8

X=88

D=(88-78)/8=10/8=1.25

For D=1.24, N(d)=0.8925

For D=1.26, N(d)=0.8962

For D=1.25,

N(d)=(0.8925+0.8962)/2=0.89435

Probability of X<88=0.89435

Probability of X>88=1-0.89435=0.10565

P(x>88)=0.10565

You can also use NORM.DIST function of excel to find cumulative probability of X=88, with Mean=78 and Standard Deviation=8

The image of excel function is attached

Clipboard Font Alignment Number Styles : * fc =NORM.DIST(88,78,8,TRUE) F G H I J 13 0.89435 15