Find the z-score for the standard normal distribution where: P(z < +a) = 0.8980

Question

I need help with this before tomorrow at 6pm.

Answer 1

Using the z table here ( http://www.stat.ufl.edu/~athienit/Tables/Ztable.pdf ):

p(z<+a)

1 - p(z>+a)

1 - p(z<-a) = 0.8980

p(z<-a) = 1 - 0.8980

p(z<-a) = 0.1020

-a = -1.27

a = 1.27

Answer 2

P(z < +a) = 0.8980  

Y axis 1.2 and X axis 0.07 to find the numbers 0.8980. Then multiply the numbers by 100 to get the percentage (0.8980)(100) = 89.800 move three decimal places. 89.8

On the positive Z score chart in row 1.2 and column 0.07 =0.8980