Answer:
Length = 120 ft
Total cost = 1500$
Step-by-step explanation:
First, to find the length of the backyard we reverse the formula (A = l * w) and divide 10,800 by 90.
10,800 ft^2 / 90 ft = 120 ft.
we can check this by plugging the length of 120 ft into the formula:
120 ft * 90 ft = 10,800 ft^2.
Next, to find the cost of the single length of fence we multiply our length (120 ft) by the cost ($12.50):
120 * 12.50 = $1500
I worked the problem by hand. First I used the equation y=mx+b to find the rule for the function. To find m which is the same as the slope you use the change in y divided by the change in x. Or the change in output divided by the change in input. The two points or coordinates used were (-2,-4) and (1,-1). Once you have the slope you use y=mx+b and substitude y by any value of y (-4 or -1) and m is the slope calculated and x would be the corresponding x to the y value used (if -4 was chosen for y then -2 would be used for x). This will be used to calculate b.
The probability that a worker chosen at random works at least 8 hours is Option C: 0.84 approx.
<h3>How to evaluate the probability of a random variable getting at least some fixed value?</h3>
Suppose the random variable in consideration be X, and it is discrete.
Then, the probability of X attaining at least 'a' is written as:

It is evaluated as:

The probability distribution of X is:
x f(x) = P(X = x)
6 0.02
7 0.11
8 0.61
9 0.15
10 0.09
Worker working at least 8 hours means X attaining at least 8 as its values.
Thus, probability of a worker chosen at random working 8 hours is
P(X ≥ 8) = P(X = 8) + P(X = 9) +P(X = 10) = 0.85 ≈ 0.84 approx.
By the way, this probability distribution seems incorrect because sum of probabilities doesn't equal to 1.
The probability that a worker chosen at random works at least 8 hours is Option C: 0.84 approx.
Learn more about probability distributions here:
brainly.com/question/14882721
I think the answer is 7 if i am not mistaking
The first, second, and fourth are right