Answer:
15.39% of the scores are less than 450
Step-by-step explanation:
Problems of normally distributed samples are solved using the z-score formula.
In a set with mean
and standard deviation
, the zscore of a measure X is given by:

The Z-score measures how many standard deviations the measure is from the mean. After finding the Z-score, we look at the z-score table and find the p-value associated with this z-score. This p-value is the probability that the value of the measure is smaller than X, that is, the percentile of X. Subtracting 1 by the pvalue, we get the probability that the value of the measure is greater than X.
In this problem, we have that:

What percentage of the scores are less than 450?
This is the pvalue of Z when X = 450. So



has a pvalue of 0.1539
15.39% of the scores are less than 450
Answer:
if you have to add it is 17
if you have to divide it is 1.5
if you have to subtract it is 16
Step-by-step explanation:
Answer:
x = -10; x = 7
Step-by-step explanation:
|2x + 3| - 6 =11
Add 6 to each side.
|2x + 3| = 17
Apply the absolute rule: If |x| = a, then x = a or x = -a.
(1) 2x + 3 = 17 (2) 2x + 3 = -17
Subtract 3 from each side
2x = 14 2x = -20
Divide each side by 2
x = 7 x = -10
<em>Check:
</em>
(1) |2(7) + 3| - 6 = 11 (2) |2(-10) + 3| - 6 = 11
|14 + 3| - 6 = 11 |-20 + 3| - 6 = 11
|17| - 6 = 11 |-17| - 6 = 1
1
17 - 6 = 11 17 - 6 = 11
11 = 11 11 = 11