Answer:
Test scores of 10.2 or lower are significantly low.
Test scores of 31 or higher are significantly high
Step-by-step explanation:
Z-score:
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:

Significantly low:
Z-scores of -2 or lower
So scores of X when Z = -2 or lower




Test scores of 10.2 or lower are significantly low.
Significantly high:
Z-scores of 2 or higher
So scores of X when Z = 2 or higher




Test scores of 31 or higher are significantly high
10. 50 is roughly around ~16% of 300. (16% is 50.1)
11. 35% of 150 would be 52.5
12. 80 is 200% of 40
The actual skate park's perimeter is 130 inches.
Explanation:
Step 1; Assume the initial garden has a width of y inches. It is given that the length is 25 inches. The perimeter of any given rectangle is twice the sum of the length and the width of the same rectangle. The initial perimeter is given as 80 inches.
Perimeter = 2 × (length of the rectange + width of the rectangle).
80 = 2 × (25 + y), 40 = 25 + y, y = 40 - 25 = 15
So the initial park has a width of 15 inches.
Step 2; Now we calculate the actual skate park's perimeter. The length is given as 50 inches and the width was found to be 15 inches.
Perimeter = 2 × (length of the rectange + width of the rectangle).
Perimeter = 2 × (50 + 15) = 2 × 65 = 130 inches.