I have no idea how to do this, so if someone could at least do one of these I’ll be grateful <3

Answer:

12 is the correct answer

The answer is D

Hope that was fast enough

Answer:

The 98% confidence interval for the mean amount spent on their child's last birthday gift is between $40.98 and $43.02.

Step-by-step explanation:

We have the standard deviation for the sample, which means that the t-distribution is used to solve this question.

The first step to solve this problem is finding how many degrees of freedom, we have. This is the sample size subtracted by 1. So

df = 24 - 1 = 23

98% confidence interval

Now, we have to find a value of T, which is found looking at the t table, with 23 degrees of freedom(y-axis) and a confidence level of [tex]1 - \frac{1 - 0.98}{2} = 0.99[/tex]. So we have T = 2.5

The margin of error is:

[tex]M = T\frac{s}{\sqrt{n}} = 2.5\frac{2}{\sqrt{24}} = 1.02[/tex]

In which s is the standard deviation of the sample and n is the size of the sample.

The lower end of the interval is the sample mean subtracted by M. So it is 42 - 1.02 = $40.98.

The upper end of the interval is the sample mean added to M. So it is 42 + 1.02 = $43.02.

The 98% confidence interval for the mean amount spent on their child's last birthday gift is between $40.98 and $43.02.

Answer:

0.3758 = 37.58% probability that at most one of her first 10 arrows hits the target

Step-by-step explanation:

For each shot, there are only two possible outcomes. Either they hit the target, or they do not. The probability of a shot hitting the target is independent of any other shot, which means that the binomial probability distribution is used to solve this question.

Binomial probability distribution

The binomial probability is the probability of exactly x successes on n repeated trials, and X can only have two outcomes.

[tex]P(X = x) = C_{n,x}.p^{x}.(1-p)^{n-x}[/tex]

In which [tex]C_{n,x}[/tex] is the number of different combinations of x objects from a set of n elements, given by the following formula.

[tex]C_{n,x} = \frac{n!}{x!(n-x)!}[/tex]

And p is the probability of X happening.

Each arrow with a probability 0.2

This means that [tex]p = 0.2[/tex]

First 10 arrows

This means that [tex]n = 10[/tex]

What is the probability that at most one of her first 10 arrows hits the target?

This is:

[tex]P(X \leq 1) = P(X = 0) + P(X = 1)[/tex]

So

[tex]P(X = x) = C_{n,x}.p^{x}.(1-p)^{n-x}[/tex]

[tex]P(X = 0) = C_{10,0}.(0.2)^{0}.(0.8)^{10} = 0.1074[/tex]

[tex]P(X = 1) = C_{10,1}.(0.2)^{1}.(0.8)^{9} = 0.2684[/tex]

Then

[tex]P(X \leq 1) = P(X = 0) + P(X = 1) = 0.1074 + 0.2684 = 0.3758[/tex]

0.3758 = 37.58% probability that at most one of her first 10 arrows hits the target

9514 1404 393

Answer:

  3.8

Step-by-step explanation:

The angle bisector divides the triangle segments proportionally.

  x/3 = 5/4

  x = 15/4 = 3.75 . . . . multiply by 3

  x ≈ 3.8

Answer: a continuous random​ variable

Step-by-step explanation:

Can you count the distance it traveled? You can't, so it couldn't be discrete because you can count discrete variables.

Can you measure the distance it traveled? You sure can, that makes it a continuous random variable.

Do you know the exact distance it's going to travel? You won't, therefore it's a random variable since you don't know the value beforehand.

Answer:

The width is 10 feet.

Step-by-step explanation:

We know that the area of a rectangle is given by the formula:

[tex]\displaystyle A=L\cdot W[/tex]

Where L is the length and W is the width.

We are given that the length of the rectangle is three times the width. In other words:

[tex]L=3W[/tex]

The total area is 300 square feet. And we want to determine the width of the rectangle.

So, substitute 300 for A and 3W for L:

[tex](300)=(3W)\cdot W[/tex]

Multiply:

[tex]300=3W^2[/tex]

Divide both sides by three:

[tex]W^2=100[/tex]

And take the principal square root of both sides. So:

[tex]W=10[/tex]

Thus, the width of the rectangle is 10 feet.

Answer:

The first mechanic charged $ 85 an hour, and the second mechanic charged $ 55 an hour.

Step-by-step explanation:

Given that two mechanics worked on a car, and the first mechanic worked for 10 hours, and the second mechanic worked for 5 hours, and together they charged a total of $ 1125, to determine what was the rate charged per hour by each mechanic if the sum of the two rates was $ 140 per hour, the following calculation must be performed:

1125/15 = X

75 = X

80 x 10 + 60 x 5 = 800 + 300 = 1100

85 x 10 + 55 x 5 = 850 + 275 = 1125

Therefore, the first mechanic charged $ 85 an hour, and the second mechanic charged $ 55 an hour.

Answer:

mehoimehoihoi

Step-by-step explanation:

The solution for set F(x) is -1

Divide total miles by speed:

360 / 50 = 7.2 hours

Answer:

x=70

Step-by-step explanation:

First, we know that the mode is the number that is the most common. As each value in the set so far only has one of each number, we know that x must be one of the current numbers, making that the mode.

Next, because x is the mode and has to be the median as well, and our number line so far is

(10, 70, 80, 120), x must be either 70 or 80 to make it the median. This is because if x is 10 or 120, we would end up with (10, 10, 70, 80, 120) with 70 as the median or (10, 70, 80, 120, 120) with 80 as the median.

Finally, to calculate the mean, we have

mean = sum / count

The mean must be x, as it is equal to the mode, so we have

x = (10+70+80+120 + x)/5 (as there are 5 numbers including x)

multiply both sides by 5 to remove the denominator

5 * x = 10+70+80+120+x

5 * x = 280 + x

subtract x from both sides to isolate the x and the coefficient

4 * x = 280

divide both sides by 4 to get x

x= 70

We see that x is 70 or 80 and is one of the current numbers, checking off all boxes.

Answer:

$ 1943

Step-by-step explanation:

You two congruent trapezoids.

Find the area of one and multiply by 2.

A = [tex]\frac{base_{1} + base_{2} }{2}[/tex] x  h

  = [tex]\frac{28+39}{2}[/tex] x 14.5

  = [tex]\frac{67}{2}[/tex] x 14.5

  = 33.5 x 14.5

  = 485.75

  = 485.75 x 2 (Two trapezoids)

  = 971.50

  = 971.50 x 2 (two dollars a square foot)

  = 1943.00

Answer:

0.1512 = 15.12% probability that fewer than four tornadoes occur in a three-week period.

Step-by-step explanation:

In a Poisson distribution, the probability that X represents the number of successes of a random variable is given by the following formula:

[tex]P(X = x) = \frac{e^{-\mu}*\mu^{x}}{(x)!}[/tex]

In which

x is the number of sucesses

e = 2.71828 is the Euler number

[tex]\mu[/tex] is the mean in the given interval.

In a given region, the number of tornadoes in a one-week period is modeled by a Poisson distribution with mean 2

Three weeks, so [tex]\mu = 2*3 = 6[/tex]

Calculate the probability that fewer than four tornadoes occur in a three-week period.

This is:

[tex]P(X < 4) = P(X = 0) + P(X = 1) + P(X = 2) + P(X = 3)[/tex]

In which

[tex]P(X = x) = \frac{e^{-\mu}*\mu^{x}}{(x)!}[/tex]

[tex]P(X = 0) = \frac{e^{-6}*6^{0}}{(0)!} = 0.0025[/tex]

[tex]P(X = 1) = \frac{e^{-6}*6^{1}}{(1)!} = 0.0149[/tex]

[tex]P(X = 2) = \frac{e^{-6}*6^{2}}{(2)!} = 0.0446[/tex]

[tex]P(X = 3) = \frac{e^{-6}*6^{3}}{(3)!} = 0.0892[/tex]

Then

[tex]P(X < 4) = P(X = 0) + P(X = 1) + P(X = 2) + P(X = 3) = 0.0025 + 0.0149 + 0.0446 + 0.0892 = 0.1512[/tex]

0.1512 = 15.12% probability that fewer than four tornadoes occur in a three-week period.

Answer:

x = 8 minutes

Step-by-step explanation:

Given that,

An internet cafe charges a fixed amount per minute to use the internet.

The cost of using the  internet in dollars is,

[tex]y=\dfrac{3}{4}x[/tex]

Where

x is the number of minutes spent on the internet

We need to find the value of x when y = $6.

So, put y = 6 in the above equation.

[tex]6=\dfrac{3}{4}x\\\\x=\dfrac{6\times 4}{3}\\\\x=8\ min[/tex]

So, 8 minutes must spent on internet.

Answer:

A={x: x is a cat}

B={x: x likes climbing on trees}

My little cat Louis likes climbing on trees (Louis is in the intersection of the two sets)

A={x: x is a town in the USA}

B={x: x is a town in the UK}

To improve my English I'd like to go on holiday to a town in the USA, but a town in the UK would work too (the town shall be in the union of the two sets)

Answer:

1/6 < 2/11

Step-by-step explanation:

1/6 = 2/12

2/11 >2/12

So that means 1/6 < 2/11

Answer:  1/6 < 2/11

This is the same as saying 11/66 < 12/66

===========================================================

Explanation:

1/6 is the same as 11/66 when multiplying top and bottom by 11.

2/11 is the same as 12/66 when multiplying top and bottom by 6.

The 6 and 11 multipliers are from the original denominators (just swapped).

We can see that 11/66 is smaller than 12/66, simply because 11 < 12, so that means 1/6 is smaller than 2/11

-----------------

Here's one way you could list out the steps

11 < 12

11/66 < 12/66

1/6 < 2/11

------------------

Here's another way to list out the steps. First assume that 1/6 and 2/11 are equal. Cross multiplication then leads to

1/6 = 2/11

1*11 = 6*2

11 = 12

Which is false. But we can fix this by replacing every equal sign with a less than sign

1/6 < 2/11

1*11 < 6*2

11 < 12

---------------------

Yet another way to see which is smaller is to use your calculator or long division to find the decimal form of each value

1/6 = 0.1667 approximately

2/11 = 0.1818 approximately

We see that 0.1667 is smaller than 0.1818, which must mean 1/6 is smaller than 2/11.

Answer:

4g+2x=r

Step-by-step explanation:

4g+r=2r-2x

collecting like terms

4g+2x=2r-r

4g+2x=r

Answer:

1.  e. Convenience sampling is used because students are chosen due to convenience of location.

2. a. University students may not be representative of all people in their age group.

Step-by-step explanation:

Samples may be classified as:

Convenient: Sample drawn from a conveniently available pool.

Random: Basically, put all the options into a hat and drawn some of them.

Systematic: Every kth element is taken. For example, you want to survey something on the street, you interview every 5th person, for example.

Cluster: Divides population into groups, called clusters, and each element in the cluster is surveyed.

Stratified: Also divides the population into groups. However, then only some elements of the group are surveyed.

Questioning students as they leave an academic building, a researcher asks 341 students about their eating habits.

Students sampled as they leave the build, which is convenience, in this case convenience of location, which means that the correct answer to question 1 is given by option e.

2. What potential sources of bias are present if any. Select all that apply.

Only members of one group are asked(university students), and this may not be representative of the rest of the population, which means that the correct answer to question 2 is given by option a.

Answer:

A proportion is an equality of two ratios.

Example : [tex]\frac{1}{3}[/tex] = [tex]\frac{x}{9}[/tex]

​

We write proportions to help us find equivalent ratios and solve for unknown quantities.

A rate is the quotient of a ratio where the quantities have different units.

Example : [tex]\frac{distance}{time}[/tex]

A ratio is a comparison of two quantities.

Example : 1 : 3 or [tex]\frac{1}{3}[/tex]

Answer:

A. 18 calls

B. 0.9

C. 20

Step-by-step explanation:

Number of representatives=2,

Number of extension lines=2,

Average calls each representative can accommodate per hour = 15 calls,

Arrival rate per hour = 30 calls

(a) 90% of the arrival rate = 0.09 × 20 = 18 calls

To handle 18 calls immediately, 18 extension lines should be used

(b) Probability is given by number of possible outcomes ÷ number of total outcomes

Number of possible outcomes = 18, number of total outcomes = 20

Probability (call will receive busy signal) = 18/20 = 0.9

(c) For one extension line, numbers of calls to receive busy signal = 20 - 10 = 10 calls

Number of calls to receive busy signal for the current telephone system with two extension lines = 2 × 10 = 20 calls

Answer:

For the perimeters, x must be equal to 2.

For the areas, it is either undefined, or something.

Step-by-step explanation:

You can first find the perimeters for both sides.

For the left shape, we add the two sides of 6 and x + 4 to get x + 10.

Then we multiply x + 10 by 2 because there are 4 sides, and we only got 2 sides.

The perimeter of the first shape is 2x + 20.

The second shape can be solved by doing the same thing by adding 2 and 3x + 4 to get 3x + 6.

3x + 6 times 2 is 6x + 12.

The second perimeter is 6x + 12.

If both sides are supposed to be equal, then we can write these two expressions we solved for like:

6x + 12 = 2x + 20.

Subtraction property of equality

6x + 12 - 12 = 2x + 20 - 12

Simplify

6x = 2x + 8

Again

6x - 2x = 2x - 2x + 8

Simplify

4x = 8

Division property of equality

4/4x = 8/4

Simplify

x = 2

So if x = 2, the perimeters will be the same.

You can confirm this by plugging it back into either equation.

For the areas, we just multiply the length and width for both shapes, so we get

6(x+4)  =  2(3x+4)

Since they are supposed to be equal.

We simplify and get

6x + 24 = 6x + 8

We know this is false and is not possible, since we can remove the 6x because it is on both sides.

We also know that 24 is not equal to 8 (who thought!)

:D

24 ≠ 8

So it is undefined or whatever you call it.

Answer:

He remained with 25 goats.

Step-by-step explanation:

35 - 10 = 25

Hope this helps.

Answer:

He remained with 25 goats

Step-by-step explanation:

35 - 10 = 25

( solution at pic)

Answer:

Step-by-step explanation:

M = S+3

W = 2M = 2(S+3) = 2S+6

M+S+W = 89

(S+3)+S+(2S+6) = 89

S = 20

Answer:

20

Step-by-step explanation:

Sarah: 21

Mary: 24

Winifred: 48

No

Sarah: 20

Mary: 23

Winifred: 46

Yes

Answer:

-2 is the answer trust me

Answer:

Step-by-step explanation:

As due to congruency,

x + 3 = 3y

[By putting the values of x = 3 and y = 2]

=> 3 + 3 = 3 × 2

=> 6 = 6

and,

x = y + 1

[By putting the values of x = 3 and y = 2]

=> 3 = 2 + 1

=> 3 = 3

Hence, proved

Step-by-step explanation:

It is Associative property, I have seen this somewhere

Answer:

The test statistics will be "-0.876",

Step-by-step explanation:

Given:

According to the question,

Level of significance will be:

= 0.05

Now,

The test statistics will be:

= [tex]\frac{\bar x-\mu}{\frac{s}{\sqrt{n} } }[/tex]

By substituting the values, we get

= [tex]\frac{18.6-19}{\frac{3.1}{\sqrt{46} } }[/tex]

= [tex]-\frac{2.713}{3.1}[/tex]

= [tex]-0.876[/tex]