An educator wants to determine whether early exposure to school will affect IQ. He enlists the aid of the parents of 12 pairs of preschool-age identical twins who agree to let their twins participate in this experiment. One member of each twin pair is enrolled in preschool for 2 years while the other member of each pair remains at home. At the end of the 2 years, the IQs of all the children are measured. The results follow.
IQ
Pair Twins at
preschool Twins at
home
1 109 116
2 122 119
3 110 106
4 119 115
5 114 118
6 112 103
7 128 125
8 114 116
9 108 107
10 117 123
11 117 116
12 106 104
Does early exposure to school affect IQ? Use α = 0.052 tail.
tobt =

Answer:

9,28

Step-by-step explanation:

see image below:)

Step-by-step explanation:

2x - 10y > -20

=> x - 5y > -10

or x - 5y +10 > 0

Answer:

[tex]x = -2; x = 5[/tex]

Step-by-step explanation:

Given

[tex]f(x) = -x^2 + 4x + 12[/tex]

[tex]g(x) = x +2[/tex]

Required

For what value of x is: [tex]f(x) = g(x)[/tex]

[tex]f(x) = g(x)[/tex] implies that

[tex]-x^2 + 4x + 12 = x + 2[/tex]

Collect like terms

[tex]-x^2 + 4x -x + 12 -2 = 0[/tex]

[tex]-x^2 + 3x + 10 = 0[/tex]

Expand

[tex]-x^2 + 5x-2x + 10 = 0[/tex]

Factorize

[tex]-x(x - 5)-2(x - 5) = 0[/tex]

Factor out x - 5

[tex](-x - 2)(x - 5) = 0[/tex]

Solve for x

[tex]-x - 2 = 0; x - 5 = 0[/tex]

So:

[tex]x = -2; x = 5[/tex]

Answer:

45 inches (choice B)

Step-by-step explanation:

The perimeter is the sum of all of the sides of a shape. Since the sides are given this problem is fairly easier than other problems. You simply have to add the numbers together.

8 + 3 + 3 + 6 + 6 + 19 = 45 inches

Answer:

45 in.

Step-by-step explanation:

Perimeter = 8 + 3 + 6 + 19 + 6 + 3

= 45.

Answer:

736 units squared (c)

Step-by-step explanation:

Took the quiz

Answer:

C. 1 and 3

Step-by-step explanation:

Answer:

x>0

I am very certain.

brainliest?

Answer:

value of x i think correct answer is 2

Answer:

5x + 3 ≥ 18

Step-by-step explanation:

when solved, the inequality is x ≥ 3

x ≥ 3 indicates all values greater than 3, including 3, should be in the solution set

Answer:

bbbb,

bbbg, bbgb, bgbb, gbbb,

bbgg, bgbg, bggb, gbgb, gbbg, ggbb,

bggg, gbgg, ggbg, gggb,

gggg

Step-by-step explanation:

3 children: bbb, bbg, bgb, gbb, bgg, gbg, ggb, ggg

4 children: bbbb, bbbg, bbgb, bgbb, gbbb, bbgg, bgbg, bggb, gbgb, ggbb, bggg, gbgg, ggbg, gggb, gggg

You need to take a methodological approach;

The 2 easiest are the possibility of all boys and all girls;

Then consider 3 boys and 1 girl:

bbbg, bbgb, bgbb, gbbb

Then 2 boys and 2 girls:

bbgg, bgbg, bggb, gbgb, gbbg, ggbb

Lastly, 1 boy and 3 girls:

bggg, gbgg, ggbg, gggb

In total, there are 16 possibilities

P.S. interesting to note is that the number of possibilities here follows the pattern of Pascal's triangle:

       1

     1   1

   1  2  1

 1  3  3  1

1  4  6  4  1

The last row is relevant here;

There is 1 possibility where there are 4 boys;

There are 4 possibilities (in terms of the order of birth) where there are 3 boys and 1 girl;

There are 6 possibilities where there are 2 boys and 2 girls

There are 4 possibilities where there is 1 boy and 3 girls;

There is 1 possibility where there are 4 girls;

The pattern ∴ is 1 4 6 4 1, as the 5th row of Pascal's triangle reads;

If your talking about 3 children, it would match the 4th row of Pascal's triangle;

So, 1 possibility of 3 boys;

3 possibilities of 2 boys and 1 girl;

3 possibilities of 1 boy and 2 girls;

And 1 possibility of 3 girls;

If your talking about 10 children, it would match the 11th row of Pascal's triangle.

(Maths can be so cool XD)

Answer:

D) 1 3/4

Step-by-step explanation:

9514 1404 393

Answer:

  Division A

Step-by-step explanation:

Suppose last year's revenue for the company was 100 units.

Last year's Division A revenue was 0.60×100 = 60. This year's revenue is 1-35% = 65% of last year's, so is ...

  60 × 0.65 = 39 . . . . units

__

Last year's Division B revenue was 0.40×100 = 40. This year's revenue is 1-5% = 95% of last year's, so is ...

  40 × 0.95 = 38 . . . . units

__

At 39 units this year, Division A still has the higher revenue than Division B at 38 units.

Answer:

If you take 5 sweet out of the basket, then the ratio of the number of chocolate to the number of sweet left in the basket is. \frac{5} {30 - 5} = 5/25 = 1/5

Step-by-step explanation:

9514 1404 393

Answer:

  $448

Step-by-step explanation:

The given formula will tell you the amount of interest earned:

  I = Prt

  I = $400·0.02·6 = $48

The account balance will be the sum of the original deposit and the interest it earns:

  $400 +48 = $448 . . . . balance after 6 years

Step-by-step explanation:

[tex]median = \frac{1.48 + 1.49}{2} [/tex]

[tex] = \frac{2.97}{2} [/tex]

[tex] = 1.485[/tex]

Answer:

A

Step-by-step explanation:

|4 − y| = 1

drop absolute value lines

create two problems

4 - y = 1

and

4 - y = -1

solve for y

Answer:

(4x+9)-(16x+9) = 4x+9-16x-9

= -12x

Answer:

acute triangle

if i m wrong please dont mind and

correct me

Answer:

5

Step-by-step explanation:

The median is the middle when the numbers are lined up from smallest to largest

3,4,4,6,7,15

There are 6 number so the middle is the  between the 3rd and 4th number

3,4,4,    6,7,15

Take the 3rd and 4th numbers and average

(4+6)/2 = 10/2 = 5

Answer:

median = 5

Step-by-step explanation:

Arrange the data in ascending order :

3 , 4 , 4 , 6 , 7 , 15

Choose the middle number.

Here there are even number of data. Take the average of the middle

numbers .

4 and 6 are the middle number. average of 4 and 6 = ( 4 + 6 ) /2 = 5

Therefore , median = 5

Step-by-step explanation:

In mathematics, a function is a mapping from set A to a set B that has a unique output for any given input. “Operators” or “operations” are typically defined as a special type of function.

Answer:

Sophie will get $3.18 back in change.

Step-by-step explanation:

You do 5.00-1.82 and you get 3.18, which is equal to the change that Sophie will get.

Answer:

80

Step-by-step explanation:

brainliest please ;>

Answer:

$21.04

Step-by-step explanation:

123.76 x 17% = 21.0392 = 21.04

Answer:

[tex]D.\ y = 3\sin(2(x + \frac{\pi}{4}))[/tex]

Step-by-step explanation:

Given

[tex]A = 3[/tex] --- Amplitude

[tex]C = \frac{\pi}{4}[/tex] --- Right phase shift

Required

Identify the function

A sinusoidal function is defined as:

[tex]y = A\sin(B(x + C)) + D[/tex]

Substitute values for A and C

[tex]y = 3\sin(B(x + \frac{\pi}{4})) + D[/tex]

By comparison, only option (D) has the above format where

[tex]y = 3\sin(2(x + \frac{\pi}{4}))[/tex]

Hence (D) is correct

Answer:

The radius of Circle D is 8 cm.

The perimeter of ΔABC is (24 + 6√7) cm.

Step-by-step explanation:

First, let the intersection point below D be K and let the intersection point between A and B be J.

Since segment BK, which passes through the center of the circle, is perpendicular to chord AC, BK also bisects AC. Hence, AK = CK.

Connect points A and D to create radius AD. Note that BD is also a radius. Hence, AD = BD.

For ΔABK, by the Pythagorean Theorem:

[tex]AB^2=(BD+1)^2+AK^2[/tex]

Since AB = 12:

[tex]144=(BD+1)^2+AK^2[/tex]

For ΔADK, by the Pythagorean Theorem:

[tex]AD^2=1^2+AK^2[/tex]

Since AD = BD:

[tex]BD^2=1+AK^2[/tex]

Subtract the second equation into the first:

[tex]144-(BD^2)=(BD+1)^2+AK^2-(1+AK^2)[/tex]

Simplify:

[tex]144-BD^2=BD^2+2BD+1-1[/tex]

Hence:

[tex]2BD^2+2BD-144=0[/tex]

Simplify:

[tex]BD^2+BD-72=0[/tex]

Factor:

[tex](BD+9)(BD-8)=0[/tex]

By the Zero Product Property:

[tex]BD=-9\text{ or } BD=8[/tex]

Since the radius must be positive, the radius is 8 cm.

Since we already know AB and BC, we need to find AC to find the perimeter.

Note that AC = AK + CK = 2AK.

From the second equation:

[tex]BD^2=1+AK^2[/tex]

Thus:

[tex]AK=\sqrt{BD^2-1}=\sqrt{(8)^2-1}=\sqrt{63}=3\sqrt{7}[/tex]

Hence:

[tex]AC=2(AK)=2(3\sqrt7)=6\sqrt7[/tex]

Therefore, the perimeter of ΔABC is:

[tex]P=(12)+(12)+(6\sqrt7)=24+6\sqrt7\text{ cm}[/tex]

Answer:

c

Step-by-step explanation:

Answer:

positive

Step-by-step explanation: