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2 years ago

The area of a rectangular field is 2275 m2. The field is enclosed by 200 m of fence. What are the dimensions of the field?

1 answer:

4 0

So it is enclosed by 200 m of fence
perimiter=200 m
it is a rectangle to
p=legnth+legnth+width+width or
p=l+l+w+w or
p=2l+2w or
p=2(l+w)
so
p=200
200=2(l+w)
divide both sides by 2
100=l+w
area=l times w
area=2275
lw=2275
l+w=100
combine and solve
l+w=100
subtract w
l=100-w
subisutute 100-w for l in other eqution
(100-w)(w)=2275
distribute
-w^2+100w=2275
add (w^2-100w) to both sides
0=w^2-100w+2275
factor
find what 2 numbers add up to -100 and multiply to get 2275
guess (or factor 2275 and find factors that add up to -100)
figure out that they are -65 and -35
0=(w-65)(w-35)
set each to zero
0=w-65
0=w-35

solve for w
w=65 or 35
65>35 so
65 m=legnth
35 m=width

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Answer:

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Step-by-step explanation:

This is a normal probability distribution question.

We'll need to standardize the 95 days to solve this.

The standardized score is the value minus the mean then divided by the standard deviation.

z = (x - xbar)/σ

x = 95 days

xbar = mean = 105 days

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To determine the probability that the project will be completed in 95 days or less, P(x ≤ 95) = P(z ≤ (-2))

We'll use data from the normal probability table for these probabilities

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2 years ago

Suppose two different methods are available for eye surgery. The probability that the eye has not recovered in a month is 0.002

umka21 [38]

Answer:

0.4007

Step-by-step explanation:

Let's define the following events:

A: method A is used

B: method B is used

NR: the eye has not recovered in a month

R: the eye is recovered in a month

The probability that the eye has not recovered in a month is 0.002 if method A is used, i.e., P(NR|A) = 0.002, so P(R|A) = 0.998.

When method B is used, the probability that the eye has not recovered in a month is 0.005, i.e., P(NR|B) = 0.005, so P(R|B) = 0.995.

40% of eye surgeries are done with method A, i.e., P(A) = 0.4

60% of eye surgeries are done with method B, i.e., P(B) = 0.6

If an eye is recovered in a month after surgery is done in the hospital, what is the probability that method A was performed? We are looking for P(A|R), then, by Bayes' Formula

P(A|R) = P(R|A)P(A)/(P(R|A)P(A) + P(R|B)P(B)) = 0.998*0.4/(0.998*0.4 + 0.995*0.6) = 0.4007

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2 years ago

You roll a colored cube with one white side, two red sides, and three blue sides. What is the expected number of red sides you w

miskamm [114]

Hello!

This is an example of theoretical probability. If you rolled the die 1,000 times, you would probably roll red about 333 times. On average, this is 1/3, and with a die it is 2/6. As you can see, it will be rolled 2/6 of the time on average, so our answer is A) 2.

I hope this helps!

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2 years ago

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Answer:

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