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3 years ago

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Briana spent 2 3/4 hours on her science project. Jackson worked 1 1/3 times as long on his science project as Briana worked. For

how many hours did Jackson work on his science project?

1 answer:

nikdorinn [45]3 years ago

8 0

3 2/3 hours. Because if you do 2 3/4 times 1 1/3 you get 11/3 which simplifies into a mixed fraction of 3 2/3.

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What is the equation of the line that passes through the point (5, -6) and has a<br> slope of 3/5

Marysya12 [62]

Answer:

y = 3/5x + -9

or y = 3/5x - 9

Step-by-step explanation:

Since you are already given the slope for this equation all you have to do is plug in the ordered pair in this equation: y = mx+b

Here is what this equation stands for:

y = the y in the order pair you are given, in this case it would be -6

m = This is the slope, sometimes you may not be given the slope so you would have to find it, but in this case, you are given it, the slope is 3/5

x = the x in the ordered pair you are given, in this case it would be 5

b = This is the y-intercept, you will mostly be solving for this most of the time

(5,-6)

(x, y)

y = mx+b (Use this Formula)

-6 = 3/5(5) +b (The numbers have been substituted within the formula)

-6 = 3+b (simplify the equation by multiplying the slope by the x)

-6-3 = b ( once simplified the left side of the equation, go to the right side, but remember when you do that you have to change the sign because you are eliminating 3 on the left side completely, "what you do on one side, do it to the other side")

-9 = b (solve)

y = 3/5x + -9 (plug in the slope and B(y-intercept) within the formula - y = mx+b, make sure that you are not plugging in x and y for this step)

I Hope This Helped You Understand this Problem Better/More!!! Stay Safe and Healthy!

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How to find the surface area

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Are you talking about area ?

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Select whether each equation has no solution, one solution, or infinitely many solutions. No Solution One Solution Infinitely Ma

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Answer:

Step-by-step explanation:

7x + 14 = 14 x + 7

-7x = -7

x = 1 (one solution)

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5 x + 8 = 8 + 5 x

0 =0 (infinite solutions)

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3 years ago

Estimate the amount of water that fits inside a kitchen sink?

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About 9 gallons (average)

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3 years ago

A geologist has collected 5 specimens of basaltic rock and 7 specimens of granite. The geologist instructs a laboratory assistan

MaRussiya [10]

The rocks are chosen without replacement, which means that the hypergeometric distribution is used to solve this question. First we get the parameters, and then we answer the questions. From this, we get that:

$E(X) = 5.25, Var(X) = 0.5966$
P(X < 6) = 0.9545
P(all specimens of one of the two types of rock are selected for analysis) = 0.2046.

Hypergeometric distribution:

The probability of x successes is given by the following formula:

$P(X = x) = h(x,N,n,k) = \frac{C_{k,x}*C_{N-k,n-x}}{C_{N,n}}$

In which:

x is the number of successes.

N is the size of the population.

n is the size of the sample.

k is the total number of desired outcomes.

Combinations formula:

$C_{n,x}$ is the number of different combinations of x objects from a set of n elements, given by the following formula.

$C_{n,x} = \frac{n!}{x!(n-x)!}$

The mean and the variance are:

$\mu = \frac{nk}{N}$

$\sigma^2 = \frac{nk(N-k)(N-n)}{N^2(N-1)}$

We have that:

5 + 7 = 12 rocks, which means that $N = 12$

9 are chosen, which means that $n = 9$

7 are granite, which means that $k = 7$

Question a:

$E(X) = \mu = \frac{9\times7}{12} = 5.25$

$Var(X) = \sigma^2 = \frac{9\times7(12-7)(12-9)}{12^2(12-1)} = 0.5966$

Thus:

$E(X) = 5.25, Var(X) = 0.5966$

Question b:

Since there are only 5 specimens of basaltic rock, at least 9 - 5 = 4 specimens of granite are needed, which means that:

$P(X < 6) = P(X = 4) + P(X = 5) + P(X = 6)$

In which

$P(X = x) = h(x,N,n,k) = \frac{C_{k,x}*C_{N-k,n-x}}{C_{N,n}}$

$P(X = 4) = h(4,12,9,7) = \frac{C_{7,4}*C_{5,5}}{C_{12,9}} = 0.1591$

$P(X = 5) = h(5,12,9,7) = \frac{C_{7,5}*C_{5,4}}{C_{12,9}} = 0.4773$

$P(X = 6) = h(6,12,9,7) = \frac{C_{7,6}*C_{5,3}}{C_{12,9}} = 0.3181$

Thus

$P(X < 6) = P(X = 4) + P(X = 5) + P(X = 6) = 0.1591 + 0.4773 + 0.3181 = 0.9545$

So P(X < 6) = 0.9545.

Question c:

5 of basaltic and 4 of granite: 0.1591 probability.

7 of granite is P(X = 7), in which

$P(X = 7) = h(7,12,9,7) = \frac{C_{7,7}*C_{5,2}}{C_{12,9}} = 0.0455$

0.1591 + 0.0455 = 0.2046, thus:

P(all specimens of one of the two types of rock are selected for analysis) = 0.2046.

A similar question is found at brainly.com/question/24008577

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3 years ago