Plzzzzz help for a brainly

Answer:

The 90% confidence interval for the difference of the population means is approximately (-17.98, -2.02).

Step-by-step explanation:

Before building the confidence interval, we need to understand the central limit theorem and subtraction of normal variables.

Central Limit Theorem

The Central Limit Theorem estabilishes 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.

For a proportion p in a sample of size n, the sampling distribution of the sample proportion will be approximately normal with mean [tex]\mu = p[/tex] and standard deviation [tex]s = \sqrt{\frac{p(1-p)}{n}}[/tex]

Subtraction between normal variables:

When two normal variables are subtracted, the mean is the difference of the means, while the standard deviation is the square root of the sum of the variances.

Boys:

Mean of 75, sample of 45, standard deviation of 25.

This means that [tex]\mu_B = 75, s_B = \frac{25}{\sqrt{45}}[/tex]

Girls:

Mean of 85, sample of 30, standard deviation of 17.

This means that [tex]\mu_G = 85, s_G = \frac{17}{\sqrt{30}}[/tex]

Distribution of the difference of mean grades of boys and girls:

[tex]\mu = \mu_B - \mu_G = 75 - 85 = -10[/tex]

[tex]s = \sqrt{s_B^2+s_G^2} = \sqrt{(\frac{25}{\sqrt{45}})^2+(\frac{17}{\sqrt{30}})^2} = 4.85[/tex]

Confidence interval:

As stated, the critical value is [tex]z = 1.645[/tex]

The margin of error is of:

[tex]M = zs = 1.645*4.85 = 7.98[/tex]

Lower bound:

[tex]\mu - M = -10 - 7.98 = -17.98[/tex]

Upper bound:

[tex]\mu + M = -10 + 7.98 = -2.02[/tex]

The 90% confidence interval for the difference of the population means is approximately (-17.98, -2.02).

Answer:

19.63cm²

Step-by-step explanation:

1/4 x π x 5² = 19.63495cm²

                  = 19.63cm²

9514 1404 393

Answer:

  y = -5x -8

Step-by-step explanation:

The y-intercept can be found from ...

  b = y -mx

Using the first point, we have ...

  b = 2 -(-5)(-2) = -8

Then the slope-intercept equation is ...

  y = mx + b . . . . . . . . for slope m and y-intercept b

  y = -5x -8

Answer:

the answer is

y=-5×-8

Step-by-step explanation:

:))

Answer:

The answer is 36

Step-by-step explanation:

Because 39+1=40

So then 40-24=16

and then divided by 6 is 36 because when you divide you multiply

Answer:

V=lwh /3

Step-by-step explanation:

Answer:

78

Step-by-step explanation:

when there is a five car diffrence its possible

Answer:

B

Step-by-step explanation:

To find the answer, translate each point and then use the process of elimination.

For the first point, the coordinates are (-4, -2). The -4 is x and the -2 is y. Translations up and down relate to the y value, while translations left and right relate to x. To translate up 4 units, add 4 to the y value of the coordinate. -2 + 4 is 2, so the y coordinate of the first point will be 2. That eliminated A and D.

For the second point, translate up 4 units (-5 + 4) and you get -1. So the y value of the second point will be -1. In option C, it is positive 1. So that leaves only B.

Answer:

Step-by-step explanation:

A hypotenuse is calculated on a triangle with a right angle. The hypotenuse is the side opposite the sides with the right angle. The equation is a^2 + b^2=c^2 where the hypotenuse is the square root of c.

Answer:

-9,-21

Step-by-step explanation:

let the numbers be x and y and x>y

x-y=12

y=2x-3

x-(2x-3)=12

x-2x+3=12

-x=12-3

-x=9

x=-9

y=2(-9)-3=-18-3=-21

Answer:

307°

Step-by-step explanation:

CF is a diameter of the circle. so, any arc connecting C and F has an arc angle of 180° (half-circle).

so, we need to add the arc angle FD.

we know the arc angle ED = 79°.

so, what is left to add is the arc angle FE.

the arc angle FE is the same as BC.

and the arc angle BC is the supplementary angle (means together they have 180°) to 132° :

BC = 180 - 132 = 48°

therefore,

the arc angle CFD = 180 + 48 + 79 = 307°

Answer:

x = 3 + 2p        (2p is 2 times p)

Answer: B,C E put as brainliest

Step-by-step explanation:

Answer:

3

Step-by-step explanation:

The formula for the Pythagorean's Theorem is a^2 + b^2 = c^2, so first you know that hypotenuse is the longest side or the opposite side from which the right angle is which in this case is the 6 so you are looking for a leg rather then the hypotenuse which means we are going to be doing subtraction.

a^2 + b^2 = c^2

√27^2 - b^2 = 6^2

27 - b^2 = 36

-27            -27

         b^2 = 9

         b^2 = √9

Answer:

It will be in the air until P(x) is zero.

P(x) = -16x2 + 32x = -16x(x - 2)

P(x) = 0 ⇒ x = 0 or x = 2

It starts on the ground at x = 0, so the total time in the air must be x = 2 seconds.

Answer:

B. (0.87, 0.48)

Step-by-step explanation:

I calculated it logically

Answer:

A.) 1 and 5

B.) -3

C.) [-1, 6]

D.) [-3, 2]

I don't know what E is

Step-by-step explanation:

She will need 6 yards. the permiter is 16 which 5 wouldnt be enough

Answer:

B. 8

Step-by-step explanation:

Based on the tangent theorem, when two tangents meet at an external point of a circle, the length of the two tangents are said to be equal in length.

Therefore:

JK = JM

Substitute

5x - 12 = x + 4

Collect like terms

5x - x = 12 + 4

4x = 16

4x/4 = 16/4

x = 4

✔️JK = 5x - 12

Plug in the value of x

JK = 5(4) - 12

JK = 20 - 12

JK = 8

Answer:

[tex]\\(x- -1)^{2} + (y- -1)^{2} = 13[/tex]

so, -1, -1 and 13

Step-by-step explanation:

1. E

2. G

3. I

4. J

5. H

6. F

7. A

8. D

9. B

10. C

Answer:

A4

Step-by-step explanation:

Answer:

54678 years

Step-by-step explanation:

Answer:

A is the most likely answer

Step-by-step explanation:

but how is this a math question?

Answer:

there is no profit there is loss because CP is greater than SP

Step-by-step explanation:

loss=CP-SP

=Rs480-Rs420

=Rs60

loss%=loss/cp*100%

=60/480*100%

=6000/480

=12.5%

Answer: 1

Step-by-step explanation:

If x = 0

then, f(x) = 1 - 0

f(x) = 1

x = ±1

Let f(x)=0

Answer:

I got C.)5

Step-by-step explanation:

Answer:

Length of AD = 10.47 meter (Approx.)

Step-by-step explanation:

Given:

Triangle ACB is a right angle triangle

Length of AC = 14.8 m

Length of CB = 5.5 m

Length of CD = 6.4 m

Find:

Length of AD

Computation:

Using Pythagorean theorem

Base = √Hypoteneus² - Perpendicular²

Length of AB = √14.8² - 5.5²

Length of AB = 13.74 m

Length of DB = √6.4² - 5.5²

Length of DB = 3.27

Length of AD = Length of AB - Length of DB

Length of AD = 13.74 - 3.27

Length of AD = 10.47

Length of AD = 10.47 meter (Approx.)

Answer:

Median income has not changed

Mean income has increased

Step-by-step explanation:

Initial number of houses = 6

Earning per household = $40,000

The initial mean :

$(40,000 * 6) / 6 = $40000

Initial median :

40000, 40000, 40000, 40000, 40000, 40000

= 1/2(n+1)th term,

Median = 40000

A 7th household earns 4,000,000

Mean = ((40000*6) + 4,000,000) / 7 = $605,714

Median = 1/2(n+1)th term

40000, 40000, 40000, 40000, 40000, 40000, 4000000

Median = 4th term = 40000

Answer: 3 miles.

Step-by-step explanation:

Since we are given the information that Ms. Wilson walked ¾miles each day. To calculate the total distance that Ms. Wilson will walk for 4 days, we have to multiply the distance walked each day by 4.

This will be:

= ¾miles × 4

= 3 miles

Therefore, Wilson walked a distance of 3 miles for the 4 days.