Use a standard normal table of the cumulative distribution function to find the value of Z when ​F(Z)equals0.90.

To find the value of Z when F(Z) = 0.90, we need to look up the value in a standard normal table (cumulative distribution function) or use a calculator.

Looking up the value in a z-table, we find that the closest value to 0.90 is 0.8997. The corresponding Z value for F(Z) = 0.8997 is approximately 1.28.

Therefore, the value of Z when F(Z) equals 0.90 is approximately 1.28.