Use technology or a z-distribution table to find the indicated area.

The scores on a standardized exam are normally distributed with a mean of 400 and a standard deviation of 50.

Approximately 40% of the scores are greater than which score?

- 370
- 387
- 413
- 430

adore.nuk Feb 28, 2018

#1**+2 **

Don't know much about this, but here's my best shot

On the z score table, 40% corresponds roughly with a z-score of about .25

So...we can solve this

z score = score - mean

____________

std deviation

.25 = score - 400

__________ multiply both sides by 50

50

50 (.25) = score - 400 add 400 to both sides

50 (.25) + 400 = score

412.5 = score ≈ 413

CPhill Feb 28, 2018