elimination was used to solve a system of equations. one of the intermediate steps led to the equation 2x= 8. which of the following systems could have led to this equation?

Answer:

The margin of error of u is of 3.8.

The 99% confidence interval for the population mean u is between 27.4 minutes and 35 minutes.

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 = 28 - 1 = 27

99% confidence interval

Now, we have to find a value of T, which is found looking at the t table, with 27 degrees of freedom(y-axis) and a confidence level of [tex]1 - \frac{1 - 0.99}{2} = 0.995[/tex]. So we have T = 2.7707

The margin of error is:

[tex]M = T\frac{s}{\sqrt{n}} = 2.7707\frac{7.3}{\sqrt{28}} = 3.8[/tex]

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

The margin of error of u is of 3.8.

The lower end of the interval is the sample mean subtracted by M. So it is 31.2 - 3.8 = 27.4 minutes

The upper end of the interval is the sample mean added to M. So it is 31.2 + 3.8 = 35 minutes

The 99% confidence interval for the population mean u is between 27.4 minutes and 35 minutes.

Step-by-step explanation:

- 8 is the ans .hope this help you. mark me as brainliest

[tex]\implies {\blue {\boxed {\boxed {\purple {\sf {D. \:= 2 {x}^{2} - \frac{1}{3} x}}}}}}[/tex]

[tex]\sf \bf {\boxed {\mathbb {STEP-BY-STEP\:EXPLANATION:}}}[/tex]

[tex] \frac{1}{3} x \: ( \: 6x - 1 \: )\\[/tex]

[tex] = \frac{x \: ( \: 6x - 1 \: )}{3}\\[/tex]

[tex] = \frac{6 {x}^{2} - x}{3} \\[/tex]

[tex] = \frac{6 {x}^{2} }{3} - \frac{x}{3}\\ [/tex]

[tex] = 2 {x}^{2} - \frac{1}{3} x\\[/tex]

[tex]\red{\large\qquad \qquad \underline{ \pmb{{ \mathbb{ \maltese \: \: Mystique35♛}}}}}[/tex]

Answer:

I'm pretty sure it's 32

Step-by-step explanation:

hope this helpsb

Answer:

the first one and the third one

Step-by-step explanation:

Answer:

Side length and perimeter of 1 face

Area of 1 face and surface area

Step-by-step explanation:

Answer:

20

Step-by-step explanation:

diameter=√(12²+16²)=√[4²(3²+4²)]=4√(9+16)=4√25=4×5=20

Answer:

4.7 * 10^8

Step-by-step explanation:

Answer:

[tex](a)\ 200 \to 249 =3[/tex]

[tex](b)\ 150 \to 199 = 0[/tex]

[tex](c)\ Total = 20[/tex]

Step-by-step explanation:

Given

See attachment for cumulative frequency histogram

Solving (a): Swimmers between 200yd and 249yd

To do this, we simply read the data from the 0 mark

From the histogram, we have:

[tex]0 \to 249 = 15[/tex]

and

[tex]0 \to 199 = 12[/tex]

So:

[tex]200 \to 249 = 0 \to 249 - 0 \to 199[/tex]

This gives:

[tex]200 \to 249 = 15-12[/tex]

[tex]200 \to 249 =3[/tex]

Solving (b): Swimmers between 150yd and 199yd

To do this, we simply read the data from the 0 mark

From the histogram, we have:

[tex]0 \to 149 = 12[/tex]

and

[tex]0 \to 199 = 12[/tex]

So:

[tex]150 \to 199 = 0 \to 199 - 0 \to 149[/tex]

This gives:

[tex]150 \to 199 = 12-12[/tex]

[tex]150 \to 199 = 0[/tex]

Solving (c): Total swimmers

To do this, we simply read the longest bar of the histogram

[tex]Longest = 20[/tex]

Hence:

[tex]Total = 20[/tex]

Answer:

27

Step-by-step explanation:

The expected count in a χ² test can be obtained thus :

Expected count for each each point in a two way table ::

(row total * column total) / total

Therefore, expected count for cell corresponding to people from United Kingdom whose favorite sport is tennis :

Row total = (51+14+86+29) = 180

Column total = (25 + 29) = 54

Total = 360

Hence,

Expected count = (180 * 54) / 360

Expected count = 27

Answer:

V = 2,495.5 ft³

Step-by-step explanation:

Volume of the given cylinder = πr²h

Where,

π = 3.14

radius (r) = ½(17) = 8.5 ft

height (h) = 11 ft

Plug in the values into the formula

V = 3.14 × 8.5² × 11

V = 3.14 × 72.25 × 11

V = 2,495.515

V = 2,495.5 ft³ (to nearest tenth)

Answer:

4-(-7)=11

-4-7=-11

-4+7=3

-7-4=-11

so neither 3 choices work

hope this helps

have a good day :)

Step-by-step explanation:

Answer:

The missing value is 5/2

Step-by-step explanation:

Answer:

Angle A = [tex]77^{o}[/tex]

Step-by-step explanation:

cos A = adjacent / hypotenuse

cos A = 18/82

cos A = 0.22

A = [tex]cos ^{-1}[/tex]0.22

A = [tex]77^{o}[/tex]

Answer:

[tex]-2\sqrt{3}+8\sqrt{5}[/tex]

Step-by-step explanation:

[tex]-2\sqrt{3} -\sqrt{5} +3\sqrt{9\times5} = -2\sqrt{3} -\sqrt{5} +3\sqrt{9}\times\sqrt{5} = -2\sqrt{3} -\sqrt{5} +9\sqrt{5} = -2\sqrt{3}+8\sqrt{5} \\[/tex]

9514 1404 393

Answer:

  D(1, 2)

Step-by-step explanation:

The ordered pair is always (x-coordinate, y-coordinate).

The x-coordinate is the distance to the right of the y-axis. (It is negative for points left of the y-axis.) Here, point D lies 1 unit right of the y-axis, so its x-coordinate is 1.

The y-coordinate is the distance above the x-axis. (It is negative for points below the x-axis). Here, point D lies 2 units above the x-axis, so its y-coordinate is 2.

The ordered pair describing the location of D is ...

  (x-coordinate, y-coordinate) = (1, 2)

Answer:

It would be Linear

Step-by-step explanation:

Answer:

i think its quadratic because the graph isnt straight and has different slopes between the x,y.

Step-by-step explanation:

Answer: x=40° and y=140°

Step-by-step explanation:

From the figure, we know that x and 40 are vertical angles. Therefore, they are equal to each other.

x=40°

With the value of x, we know that x and y are supplementary angles. That means they are equal to 180°.

40+y=180       [subtract both sides by 40]

y=140°

Now we know x=40° and y=140°.

Answer:

the value of x is 29° which is b

Answer:

The probability is 1 subtracted by the p-value of [tex]Z = \frac{X - \mu}{\frac{\sigma}{\sqrt{n}}}[/tex], in which X is the value we want to find the probability of the sample mean exceeding, [tex]\mu[/tex] is the population mean, [tex]\sigma[/tex] is the standard deviation of the population and n is the size of the sample.

Step-by-step explanation:

To solve this question, 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 [tex]\mu[/tex] and standard deviation [tex]s = \frac{\sigma}{\sqrt{n}}[/tex].

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

Central Limit Theorem for the sample mean:

Sample of size n, and thus:

[tex]s = \frac{\sigma}{\sqrt{n}}[/tex]

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

Probability of the sample mean exceeding a value:

The probability is 1 subtracted by the p-value of [tex]Z = \frac{X - \mu}{\frac{\sigma}{\sqrt{n}}}[/tex], in which X is the value we want to find the probability of the sample mean exceeding, [tex]\mu[/tex] is the population mean, [tex]\sigma[/tex] is the standard deviation of the population and n is the size of the sample.

Answer:

13.96units

Step-by-step explanation:

To get the length of CD, we will use the cosine rule as shown:

CD² = DE²+CE²-2(DE)(CE)cos m<E

Substitute the given values

CD² = 14²+9²-2(14)(9)cos71

CD² = 196 + 81 - 252cos71

CD² =277 - 252cos71

CD² = 277 - 82.0431

CD² = 194.95682

CD = √194.95682

CD = 13.96 units

Hence the length of CD of 13.96units

Answer:

Ac CA is your answer

Step-by-step explanation:

MARK ME AS BRAINLIEST

AC and CA

Step-by-step explanation:

[tex]line \: which \: has \: endpoint \: \\ \\ A \: and \: C \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \\ \\ it \: shows \: that \: line \: starts \: from \: \\ \\ A \: \: and \: ends \: with \: C \\ \\ so \: \: its \: name \: is \: \: \: \: AC \\ \\ hope \: it \: is \: helpful \: to \: you....[/tex]

Answer:

3

Step-by-step explanation:  6  11 10  48

spent $504

hair dryers cost $8 each

6 floors with the same number of rooms on each floor.

Money spent / hair dry cost  =  number of hair dryers bought

number of hair dryers   = number of floors  =  hair dryers per floor Plus any remainder

    504 /  8  =  63 hair dryers  

    63 / 6   =    10.5     so 10 rooms per floor = 60 hairs dryers with 3 left over

Answer:

well IMA just copy the other guy and say 3

Step-by-step explanation:

just cause it is.

Answer:

100°

Step-by-step explanation:

the lower right angle is 180-149 = 31°

the sum of all three angles in a triangle is 180°.

so the solution is 180-31-49

152 cubic ft

Answer:

Volume of solid figure=Volume of

upper cuboid+volume of lower cuboid

=l*b*h+l*b*h=10*4*3+4*4*2=152 cubic ft

152 cubic ft

Answer:

Volume of solid figure=Volume of

upper cuboid+volume of lower cuboid

=l*b*h+l*b*h=10*4*3+4*4*2=152 cubic ft

Answer:

B = (3,3)

Step-by-step explanation:

The order pair of B is (3,3)

3 is x component

3 is y component