Answer:
Step-by-step explanation:
Surface area = lateral area + 2(area of base)
Lateral area = perimeter of base * height.
Because it is a isosceles right triangle, both sides are equal.
= 72
2 = 72. Divide both sides by 2
= 36. Square both sides.
x = 6.
So the perimeter of the base = 6 + 6 + = 20.485281374239
Lateral area = 20.485281374239 * 7 = 143.397
Area of base is (1/2)base * height.
(1/2)(6)(6) = 18
Using the surface area formula
surface area = 143.397 + 2(18) = 179.4
Answer:
95.64% probability that pledges are received within 40 days
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 is the probability that pledges are received within 40 days
This is the pvalue of Z when X = 40. So
has a pvalue of 0.9564
95.64% probability that pledges are received within 40 days