Question

On a standardized test with a normal distribution, the mean was 64.3 and the standard deviation was 5.4. what percentile is a 74?

Answer 1

You'll need to use a Z-table for this one.
First, Z = (X - mean)/(Standard deviation), where X is the given value.
Z = (74-64.3)/5.4= 1.80
Next, look up 1.80 in the Z table.

Answer 2

The table value at Z = 1.80 is 0.0359. The percentile can be calculated as
(1-0.0359)*100=96.41 percentile

Answer 3

ok next between what two values does 68.2% of the distribution lie?

Answer 4

68.2% of data will fall within one standard deviation of the mean

Answer 5

so, 64.3-5.4=58.9 is the lower bound and
64.3+5.4=69.7 is the upper

Answer 6

ok thanks