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1 year ago

Jack is 27 years older than Susan. In 5 years he will be 4 times as old as she is. Find the present ages of jack and Susan

1 answer:

riadik2000 [5.3K]1 year ago

5 0

X - Jack's age
y - Susan's age

Jack is 27 years older than Susan.
$x=y+27$

In 5 years he will be 4 times as old as she is.
$x+5=4(y+5)$

The system of equations:
$x=y+27 \\ x+5=4(y+5) \\ \\ \hbox{substitute y+27 for x in the 2nd equation:} \\ y+27+5=4(y+5) \\ y+32=4y+20 \\ y-4y=20-32 \\ -3y=-12 \\ y=\frac{-12}{-3} \\ y=4 \\ \\ x=y+27=4+27=31$

Jack is 31 years old and Susan is 4 years old.

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To increase sales, a local donut shop began putting an extra donut in some of the boxes. Customers are unaware of which boxes ha

Bingel [31]

Answer:

Step-by-step explanation:

Hello!

Part A

First, determine your study variable:

X: Number of boxes with an extra donut in a sample of eight.

To see if the variable has a Binomial distribution you have to check if the binomial criteria are met:

1. The number of observation of the trial is fixed (In this case n = 8, the boxes each customer bought make the sample)

2. Each observation in the trial is independent, this means that none of the trials will affect the probability of the next trial (In this case, the amount of donuts in one box does not affect on the probability of the next box having an extra donut)

3. The probability of success in the same from one trial to another (In this case our "success" will be that the box has an extra donut, according to the owners claim that is 1/7; ρ=0,14)

So X≈ Bi (n;ρ)

Where n represents the sample (n=8) and ρ is the probability of success (ρ=0.14)

Part B

The mean of the binomial distribution is E(X)= nρ

E(X)= 8 * 0.14= 1.12

The mean of the distribution is also called the expected value. You'd expect that 1.12 boxes have an extra donut.

The variance of the binomial distribution is V(X)= nρ(1 - ρ)

V(X)= 8*0.14*(1 - 0.14)= 0.9632

Its square root is the standard deviation

√V(X)= 0.98

The standard deviation is a measure of dispersion, it indicates how much the values of the distribution of the central value are separated. In this case, 0.98 indicates that the distribution of the number of boxes with an extra donut is far from the expected value.

Part C

Two of the eight customers buy a box with an extra donut, symbolically:

P(X=2) = P(X≤2) - P(X≤1)= 0.91 - 0.68 = 0.22

There is a 22% chance that two customers bought a box with an extra donut.

Compute:

P(X≥2)= 1 - P(X<2)= 1 - P(X≤1)= 1 - 0.68= 0.32

There is a 32% chance that two or more customers bought a box with an extra donnut.

I hope it helps!

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1 year ago

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For this case we have the following equation:
$7x - 10y = 3
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From here, we must substitute ordered pairs of the form:
(x, y)
If the ordered pair satisfies the equation, then it belongs to the line.
We have then:

For (8, 5):
We substitute the following values:
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y = 5

7 (8) - 10 (5) = 3

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We observe that the equation is not satisfied and therefore, this point does not belong to the line.
Since one of the points does not belong to the line, then the equation is not a good model.

Answer:
It is not a good model. One of the points does not belong to the line.

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Answer:

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Step-by-step explanation:

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Substitute the values given:

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Use a calculator to solve and you will get ~11.03 million.

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SinB = 9/41

I explained my reasoning down below

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2 years ago

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