The formula for a trapezoid relates the area A, the two bases, a and b, and the height, h. Solve for a
1 answer:
Answer:
Step-by-step explanation:
we know that
The formula to calculate the area for a trapezoid is equal to
where
a and b are the parallel bases
h is the height of trapezoid
A is the area
<em>Solve for a</em>
That means ----> isolate the variable a
Multiply by 2 both sides to remove the fraction in the right side
Divide by h both sides
Subtract b both sides
Rewrite
You might be interested in
Answer:
B) 0.0069
Step-by-step explanation:
To solve this question, we need to understand the normal probability distribution and the central limit theorem.
Normal probability distribution
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.
Central Limit Theorem
The Central Limit Theorem estabilishes that, for a normally distributed random variable X, with mean and standard deviation
, the sampling distribution of the sample means with size n can be approximated to a normal distribution with mean
and standard deviation
.
For a skewed variable, the Central Limit Theorem can also be applied, as long as n is at least 30.
In this question, we have that:
Find the probability that their mean rebuild time exceeds 9.1 hours.
This is 1 subtracted by the pvalue of Z when X = 9.1. So
By the Central Limit Theorem
has a pvalue of 0.9931
1 - 0.9931 = 0.0069
So the answer is B.