A certain mental development index for infants is a standardized measure used in observing infants over time. It is approximately normal with a mean of 99 and a standard deviation of 19. Find the z-score corresponding to the upper quartile (Q3) of a normal distribution.

0.67449

Step-by-step explanation:

Let be the  3rd quartile of normal distribution  .

-z-score corresponding to the upper quartile can be calculated in excel as:

-The output is 0.67449. Hence, the z-score corresponding to the upper quartile (Q3) of a normal distribution is 0.67499

answer: procent 54 wynosi 33,33%

answer: about 22.67

step-by-step explanation: