what z score forms the boundary between the highest 35% and the rest of the scored?
To find the z-score that forms the boundary between the highest 35% and the rest of the scores, you can make use of the standard normal distribution table or a calculator.
The highest 35% corresponds to the area under the curve to the right of the z-score. Conversely, the remaining portion (rest of the scores) represents the area under the curve to the left.
Using a standard normal distribution table, you can find the z-score that corresponds to a cumulative area of 0.65 (1 - 0.35).
Alternatively, using a calculator or statistical software, you can directly calculate the z-score that corresponds to the cumulative percentile of 0.65.
Either option will give you the z-score that forms the boundary between the highest 35% and the rest of the scores.