The length of a rectangle is 15 ft greater than its width. If each dimension is decreased by 2 ft, the area will be decreased by
1 answer:
Answer:
length = 35ft, width = 20ft
Step-by-step explanation:
We are working with length (L), width (W), and area (A). We are asked to find the 2 dimensions. The question tells us that L = W + 15, so we can express L in terms of W. However, we still don't know what A is. Since we have 2 unknowns, we somehow need to develop 2 equations to get a solvable system.
We can set up the first equation using the relationship between L and W:
We can set up the second equation using the information in the second sentence:
Now we can plug the first equation, already isolated for A, into the second equation and solve for W:
A pretty nasty-looking equation actually becomes pretty easy to solve. We know the length is 15ft greater than the width, so if W=20, L=35.
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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
Answer:
Step-by-step explanation:
The position function is
and if we are looking for the time t it takes for the ball to hit the ground, we are looking for the height of the ball when it is on the ground. Of course the height of anything on the ground is 0, so if we set s(t) = 0 and solve for t, we will find our answer.
and factor that however you are currently factoring in class to get that
t = -.71428 seconds or
t = 1.42857 seconds (neither one of those is rational so they can't be expressed as fractions).
We all know that time will never be a negative value, so the time it takes this ball to hit the ground is
1.42857 seconds (round how you need to).