Jimmy thought he had purchased 7 folders, but purchased 6. What was his percent error?

Answer:

y = 64/3

x = -119/3

Step-by-step explanation:

3х + 6у = 9 => 5*3x+5*6у = 9*5 => 15x+30у=45 (1)

5х + 7y = -49 => 3*5x + 3*7y = -49*3 => 15x+21y=-147 (2)

(1)-(2) => 9y = 192 => y = 64/3

x = -119/3

Answer:

[tex]A"B" = \frac{AB}{2}[/tex]

Step-by-step explanation:

Given

[tex]k = \frac{1}{2}[/tex] --- scale factor

Required

Relationship between AB and A"B"

[tex]k = \frac{1}{2}[/tex] implies that the sides of A"B"C" are smaller than ABC

i.e.

[tex]A"B" = k * AB[/tex]

[tex]A"B" = \frac{1}{2} * AB[/tex]

This gives:

[tex]A"B" = \frac{AB}{2}[/tex]

Answer:

hgfyjtdjtrxgfyfguktfkgh

Step-by-step explanation:

hgfytrdutrc

Answer:

0.1003 = 10.03% probability that a simple random sample of size n= 10 results in a sample mean greater than 40 inches.

Gestation periods:

1) 0.3539 = 35.39% probability a randomly selected pregnancy lasts less than 260 days.

2) 0.0465 = 4.65% probability that a random sample of 20 pregnancies has a mean gestation period of 260 days or less.

3) 0.004 = 0.4% probability that a random sample of 50 pregnancies has a mean gestation period of 260 days or less.

4) 0.9844 = 98.44% probability a random sample of size 15 will have a mean gestation period within 10 days of the mean.

Step-by-step explanation:

To solve these questions, we need to understand the normal probability distribution and the central limit theorem.

Normal Probability Distribution

Problems of normal distributions can be solved using the z-score formula.

In a set with mean [tex]\mu[/tex] and standard deviation [tex]\sigma[/tex], the z-score of a measure X is given by:

[tex]Z = \frac{X - \mu}{\sigma}[/tex]

The Z-score measures how many standard deviations the measure is from the mean. After finding the Z-score, we look at the z-score table and find the p-value associated with this z-score. This p-value is the probability that the value of the measure is smaller than X, that is, the percentile of X. Subtracting 1 by the p-value, we get the probability that the value of the measure is greater than X.

Central Limit Theorem

The Central Limit Theorem establishes that, for a normally distributed random variable X, with mean [tex]\mu[/tex] and standard deviation [tex]\sigma[/tex], the sampling distribution of the sample means with size n can be approximated to a normal distribution with mean

For a skewed variable, the Central Limit Theorem can also be applied, as long as n is at least 30.

The height, X, of all 3-year-old females is approximately normally distributed with mean 38.72 inches and standard deviation 3.17 inches.

This means that [tex]\mu = 38.72, \sigma = 3.17[/tex]

Sample of 10:

This means that [tex]n = 10, s = \frac{3.17}{\sqrt{10}}[/tex]

Compute the probability that a simple random sample of size n= 10 results in a sample mean greater than 40 inches.

This is 1 subtracted by the p-value of Z when X = 40. So

[tex]Z = \frac{X - \mu}{\sigma}[/tex]

By the Central Limit Theorem

[tex]Z = \frac{X - \mu}{s}[/tex]

[tex]Z = \frac{40 - 38.72}{\frac{3.17}{\sqrt{10}}}[/tex]

[tex]Z = 1.28[/tex]

[tex]Z = 1.28[/tex] has a p-value of 0.8997

1 - 0.8997 = 0.1003

0.1003 = 10.03% probability that a simple random sample of size n= 10 results in a sample mean greater than 40 inches.

Gestation periods:

[tex]\mu = 266, \sigma = 16[/tex]

1. What is the probability a randomly selected pregnancy lasts less than 260 days?

This is the p-value of Z when X = 260. So

[tex]Z = \frac{X - \mu}{\sigma}[/tex]

[tex]Z = \frac{260 -  266}{16}[/tex]

[tex]Z = -0.375[/tex]

[tex]Z = -0.375[/tex] has a p-value of 0.3539.

0.3539 = 35.39% probability a randomly selected pregnancy lasts less than 260 days.

2. What is the probability that a random sample of 20 pregnancies has a mean gestation period of 260 days or less?

Now [tex]n = 20[/tex], so:

[tex]Z = \frac{X - \mu}{s}[/tex]

[tex]Z = \frac{260 - 266}{\frac{16}{\sqrt{20}}}[/tex]

[tex]Z = -1.68[/tex]

[tex]Z = -1.68[/tex] has a p-value of 0.0465.

0.0465 = 4.65% probability that a random sample of 20 pregnancies has a mean gestation period of 260 days or less.

3. What is the probability that a random sample of 50 pregnancies has a mean gestation period of 260 days or less?

Now [tex]n = 50[/tex], so:

[tex]Z = \frac{X - \mu}{s}[/tex]

[tex]Z = \frac{260 - 266}{\frac{16}{\sqrt{50}}}[/tex]

[tex]Z = -2.65[/tex]

[tex]Z = -2.65[/tex] has a p-value of 0.0040.

0.004 = 0.4% probability that a random sample of 50 pregnancies has a mean gestation period of 260 days or less.

4. What is the probability a random sample of size 15 will have a mean gestation period within 10 days of the mean?

Sample of size 15 means that [tex]n = 15[/tex]. This probability is the p-value of Z when X = 276 subtracted by the p-value of Z when X = 256.

X = 276

[tex]Z = \frac{X - \mu}{s}[/tex]

[tex]Z = \frac{276 - 266}{\frac{16}{\sqrt{15}}}[/tex]

[tex]Z = 2.42[/tex]

[tex]Z = 2.42[/tex] has a p-value of 0.9922.

X = 256

[tex]Z = \frac{X - \mu}{s}[/tex]

[tex]Z = \frac{256 - 266}{\frac{16}{\sqrt{15}}}[/tex]

[tex]Z = -2.42[/tex]

[tex]Z = -2.42[/tex] has a p-value of 0.0078.

0.9922 - 0.0078 = 0.9844

0.9844 = 98.44% probability a random sample of size 15 will have a mean gestation period within 10 days of the mean.

Answer:

2w<23

Step-by-step explanation:

The product of w and 2 mean that w multiplied by 2

Answer: 32 room

Step-by-step explanation:

[tex]7\frac{3}{4} =\frac{4(7)+3}{4} =\frac{28+3}{4} =\frac{31}{4}=7.75[/tex]

If 1 room = 7.75 yd of carpet ⇒ x rooms = 250 yd of carpet

Use proportions & cross-multiply to solve:

[tex]\frac{1}{7.75} =\frac{x}{250}\\7.75x=250\\x=\frac{250}{7.75} =32.258[/tex]

So 250 yd of carpet can cover about 32 rooms.

Answer:

x= -3

Step-by-step explanation:

2x+14= 8

2x= -6

x = -3

Answer:

-3

Step-by-step explanation:

According to the question,

[tex]\longrightarrow[/tex] CE = CD + DE

[tex]\longrightarrow[/tex] 8 = (x + 10) + (x + 4)

[tex]\longrightarrow[/tex] 8 = x + 10 + x + 4

[tex]\longrightarrow[/tex] 8 = 2x + 14

[tex]\longrightarrow[/tex] 8 ― 14 = 2x

[tex]\longrightarrow[/tex] ―6 = 2x

[tex]\longrightarrow[/tex] ―6 ÷ 2 = x

[tex]\longrightarrow[/tex] –3 = x

Therefore, the value of x is ― 3.

Answer:

1/2 or 50-50

Step-by-step explanation:

1/4 +1/4 = 1/2 or 50-50

Answer:

[tex]\frac{AB}{BC} = \frac{CE}{ED}[/tex]

Step-by-step explanation:

Given

The attached proof

Required

Complete the missing piece

In (a), we have:

[tex]\triangle ABC \to \triangle CED[/tex]

This implies that, the following sides are similar:

[tex]AB \to CE[/tex]

[tex]AC \to CD[/tex]

[tex]BC \to ED[/tex]

An equation that compares the triangle can be any of:

[tex]\frac{AB}{BC} = \frac{CE}{ED}[/tex]

[tex]\frac{AB}{AC} = \frac{CE}{CD}[/tex]

.....

From the options;

[tex]\frac{AB}{BC} = \frac{CE}{ED}[/tex] is true

Answer:

16. false

17. True

18. True

19. True

20. false

Step-by-step explanation:

16. all terms are expressions of weather - except for cold snow. "snowfall" would be the weather condition. "snow" itself is the accumulated mass of snowflakes on the ground.

17. that is simply true. there is nothing really to explain.

18. the same as 17. that is the definition of weather.

19. yes, that is part of the explanation of the difference between weather and climate.

20. South North is NOT a direction. it kind of contradicts itself. and what is between South and North ? East and West. so, even from that perspective it is not clear.

overall, what kind of math question is that ? that is more for geography, Earth science, or meteorology or something like this.

Answer:

just combine like terms, its that simple.

Step-by-step explanation:

Answer:

A is that answer

A) y<2x-3

Step-by-step explanation:

For an equation of form Ax + By = C, we are given A, B, and C.

The x intercept is when the line/equation is on the x axis, or when y=0.

Therefore, if we plug y=0 into the equation Ax+By=C, and anything multiplied by 0 is equal to 0, we can say that

Ax + 0 = C

Ax = C

divide both sides by A

x  = C/A

Therefore, the x intercept is equal to C/A

Similarly, for the y intercept, or when the line is on the y axis (or when x=0), we have

A*0 + By = C

By = C

divide both sides by B

y= C/B at the y intercept

Answer:

(D.) 3x^2 + 6x

Step-by-step explanation:

the other options aren't complete and some don't even create a parabola.

Answer:

The answer is the third one below

Answer:

It has a side that is 9 units long.

Step-by-step explanation:

Answer:

B) It has a side that is 9 units long.

Step-by-step explanation:

Since it does not have two angles on the X-axis, a side that lies on the X-axis, or an obtuse angle the reasonable answer would be B as it is true, and all of the others are false.

Step-by-step explanation:

I think substitution would be the easiest since you already have one of the variables solved for.

[tex]y=-x^2+4x+5\\y=x+1\\x+1=-x^2+4x+5\\x^2-3x-4=0\\(x-4)(x+1)=0\\x-4=0\\x=4\\x+1=0\\x=-1[/tex]

(You can just set the equations equal to each other since they both equal y).

Now, to get the points, plug in x = 4 and x = -1 into one of the equations (I'm going to plug them into y = x+1 because that one is much simpler)

[tex]y(4)=4+1\\y(4)=5\\y(-1)=-1+1\\y(-1)=0[/tex]

So, your final points are:

(4,5) and (-1,0)

Answer: A

Step-by-step explanation:

We can use substitution to solve this problem. Since we are given y=-x²+4x+5 and y=x+1, we can set them equal to each other.

-x²+4x+5=x+1        [subtract both sides by x]

-x²+3x+5=1            [subtract both sides by 1]

-x²+3x+4=0

Now that we have the equation above, we can factor it to find the roots.

-x²+3x+4=0           [factor out -1]

-1(x²-3x-4)=0         [factor x²-3x-4]

-1(x+1)(x-4)=0

This tells us that x=-1 and x=4.

We can narrow down our answer to A, but let's plug in those values to be sure it is correct.

-(-1)²+4(-1)+5=(-1)+1      [exponent]

-1+4(-1)+5=-1+1              [multiply]

-1-4+5=-1+1                    [add and subtract from left to right]

0=0  

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

-(4)²+4(4)+5=(4)+1      [exponent]

-16+4(4)+5=4+1           [multiply]

-16+16+5=4+1              [add and subtract from left to right]

5=5

Therefore, we can conclude that A is the correct answer.

Answer:

Domain: (-∞, 1]

Range: (-∞, 3]

Step-by-step explanation:

The function starts at point (1, 3) and goes to the left and down forever.

Domain: (-∞, 1]

Range: (-∞, 3]

Answer:

Domain: [tex](-\infty, 1][/tex]

Range: [tex](-\infty, 3][/tex]

Step-by-step explanation:

The domain of a function represents the range of x-values that are part of the function, read left to right. We can see that the function goes forever to the left and stops at [tex]x=1[/tex] when we read left to right. Therefore, the domain of this function is [tex]\boxed{(-\infty, 1]}[/tex].

The point at [tex]x=1[/tex] is a filled-in solid dot so it is included as part of the function. Use square brackets to denote inclusive.

The range of a function represents all y-values that are part of the function, read bottom to top. The function continues down forever and stops at [tex]y=3[/tex] when read bottom to top. Therefore, the range of this function is [tex]\boxed{(-\infty, 3]}[/tex]. Similar to the domain, we use a square bracket on the right to indicate that [tex]y=3[/tex] is included in the function. If the dot was not filled-in, then we would use a parenthesis to indicate that [tex]y=3[/tex] would not be part of the function.

Answer:

a) The margin of error for a 98% confidence interval is of 3.388 people.

b) The 98% confidence interval for the population mean is between 20.61 people and 27.39 people.

Step-by-step explanation:

We have the standard deviation for the sample, which means that the hypergeometric 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 = 15 - 1 = 14

98% confidence interval

Now, we have to find a value of T, which is found looking at the t table, with 14 degrees of freedom(y-axis) and a confidence level of [tex]1 - \frac{1 - 0.98}{2} = 0.99[/tex]. So we have T = 2.624

The margin of error is:

[tex]M = T\frac{s}{\sqrt{n}} = 2.624\frac{5}{\sqrt{15}} = 3.388[/tex]

In which s is the standard deviation of the sample and n is the size of the sample. This means that the answer to question a is of 3.388.

Question b:

The lower end of the interval is the sample mean subtracted by M. So it is 24 - 3.39 = 20.61 people

The upper end of the interval is the sample mean added to M. So it is 24 + 3.39 = 27.39 people.

The 98% confidence interval for the population mean is between 20.61 people and 27.39 people.

Answer:23

Step-by-step explanation:

Answer:

19.3 miles per gallon

Step-by-step explanation:

First, subtract 54,042.8-53,737.7. The answer is 305.1

Then, find the unit rate. 305.1/15.8

You get 19.31012658. The prompt says to round to the nearest tenth, so round, and you get 19.3.

That's your answer!

Answer:

Range: { 0,3,5,7,9}

Step-by-step explanation:

The range is the values that y takes

Range: { 0,3,5,7,9}

Now we have to find,

The range of the table of values,

→ Range = ?

Then the range will be the numbers that is in the Y column.

→ Range = ?

→ Range = (value that Y takes)

→ Range = 0,3,5,7,9

Therefore, the range is 0,3,5,7,9.

Step-by-step explanation:

x=-6 y= 0

x0 y= -1

y=mx+b

b= -1

0= -6m -1

-6m= 1

m= -1/6

parallel lines have the same slope

slope = -1/6

[tex]f(x)=\sqrt{x} -2[/tex] is the correct option

Answer:

75

Step-by-step explanation:

She is in the negatives right now so add 40 to get Celicia points equal to 0. Then add an extra 35 points (which is what she ended with). Overall, she gained 75 points to end with 35.

Answer:

45/16

Step-by-step explanation:

[tex]1 \frac{1}{4} = 4[/tex]

[tex]x = 9 [/tex]

[tex]x = 1 \frac{1}{4} \times 9 \div 4[/tex]

[tex]x = \frac{5}{4} \times 9 \div 4[/tex]

[tex]x = \frac{45}{16} [/tex]

Answer:

Step-by-step explanation:

[tex]h(t)=-16t^2+96t\\\\h(t)=-t(16t-96)[/tex]

[tex]96=2^5*3\\\\16=2^4\\\\h(t)=-t(2^5*3*t-2^4)=-2^4t(2^1*3*t-1)\\\\h(t)=-16t(6t-1)[/tex]

the b) part is easy do it!

Answer:

the answer is c

Step-by-step explanation:

the answer is c

9514 1404 393

Answer:

  (b)  He is correct. The tea will cool exponentially since it cools at a percentage rate every minute.

Step-by-step explanation:

Newton's Law of Cooling says the change in temperature is proportional to the temperature. This relation gives rise to an exponential function describing the temperature.

In this description, the temperature referred to is the difference between the temperature of the object and the temperature of the environment to/from which heat is being transferred.

Juan is only partially correct. The function is exponential, but the temperature that should be used in his equation is not the temperature of the tea, but the temperature difference between the tea and his desk.

__

The curve is not linear and not parabolic, excluding the other answer choices.

Step-by-step explanation:

Since an interior angle is 150 degrees, its adjacent exterior angle is 30 degrees.  Exterior angles of any polygon always add up to 360 degrees.  With the polygon being regular, we can just divide 360 by 30 to get 12 sides.