please help me! :(
i'll mark you brainliest <3 20 point
(maths)

Answer:

The formula for the point biserial correlation coefficient is:

point biserial correlation formula

M1 = mean (for the entire test) of the group that received the positive binary variable (i.e. the “1”).

M0 = mean (for the entire test) of the group that received the negative binary variable (i.e. the “0”).

Sn = standard deviation for the entire test.

p = Proportion of cases in the “0” group.

q = Proportion of cases in the “1” group.

Most people won’t work this formula by hand as most statistical software packages can calculate the coefficient for you.

Answer:

11

Step-by-step explanation:

5+6=11

Have a great day!!!

Answer:

y=-5/4x-10

Step-by-step explanation:

(✿◡‿◡) <-- she wants Brainliest

Answer:

p=195

Step-by-step explanation:

If m = 65 and v = 3,

when two variables are together like that, that means you multiply,

65*3 = 195

Answer:

195

Step-by-step explanation:

p=mv

p=65 times 3

p=195

Answer:

100% increase

Step-by-step explanation:

Answer: It should be 24 because Ray SP is an angle bisector

Step-by-step explanation:

Answer:

96 dollars....

Step-by-step explanation:

divide 24 by 5

which is 4.8

which represents that it costs 4 dollars and 80 cents for one dinner

multiply 4.8 and 20

which is 96

Answer:

3x^2 - 3x + 18

Step-by-step explanation:

x*3x=3x^2

(x*6)+(-3*3x)=-3x

-3*6=-18

Answer:

-7 and -8  

Step-by-step explanation:

because 7 times 8 equals 56 and negative times a negitive equals a positive and -7 added to -8 equals -15

The pair of numbers which fulfill the given condition 2.6 & -1.76

and -17.6 & 2.6.

An equation is quadratic in form if it can be written in the form of ax + bx + c = 0, where a, b, and c are constants and x is the variable.

Let x and y be the two numbers we're trying to find. We know that:

x * y = 56 (equation 1)

x + y = -15 (equation 2)

y = -15 - x (equation 3)

Substituting equation 3 into equation 1, we get:

x * (-15 - x) = 56

-x² - 15x + 56 = 0

x² + 15x - 56 = 0

Using the quadratic formula, we get:

x = (-b ± √(b² - 4ac)) / 2a

where a = 1, b = 15, and c = -56.

Substituting the values, we get:

x = (-15 ± 20.2) / 2

x = (-15 + 20.2) / 2 = 2.6

x = (-15 - 20.2) / 2 = -17.1

For x = 2.6:

y = -15 - x = -15 - 2.6 = -17.6

So, one possible pair of numbers is x = 2.6 and y = -17.6.

For x = -17.1:

y = -15 - x = -15 - (-17.1) = 2.1

So, another possible pair of numbers is x = -17.1 and y = 2.1.

Therefore, the two numbers that multiply to 56 and add to -15 are approximately -17.1 and 2.6, or vice versa.

To know more about quadratic equation check:

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Answer:a

Step-by-step explanation:

2(10*6)+2(6*19)+2(10*19)=728

Answer:

Milky way galaxy

Step-by-step explanation:

Mark me branliest please<3

Answer:

x= 1.125

Step-by-step explanation:

first we want to get the variable by itself so divide

just divide 45 by 40

Answer:

-7°C

Step-by-step explanation:

Freezing point of water = 0°C

By adding salt, freezing point lowers by 7°C ;

The freezing point of salt water can be expressed as ;

Since temperature lowers :

Freezing point of salt water :

Freezing point of water - 7°C

0°C - 7°C

= - 7°C

Let the number be n.

Now, "seven less than a number" means we subtract 7:-

n-7

This expression is equal to 18:-

[tex]\sf{n-7=18}[/tex]

[tex]\mathcal{SOLUTION:-}[/tex]

[tex]\bigstar{\boxed{\pmb{n=25}}}[/tex]

Hope everything is clear; if you need any clarification/explanation, kindly let me know, and I will comment and/or edit my answer :)

Answer:

40 inches

Step-by-step explanation:

16 * (30/12) = 40

Answer:

PQ = 40

Step-by-step explanation:

First, set up a proportion:

[tex]\frac{12}{16} =\frac{30}{x}[/tex]

Then, cross-multiply and solve:

[tex]12x = 16(30)[/tex]

[tex]12x = 480\\\\\frac{480}{12x} \\\\PQ = 40[/tex]

Hope this helped!

Answer:

50 feet below sea level. First, look for keywords. The word “below” means you will need to use a negative integer. The answer is -50.

Step-by-step explanation:

hope this helps...

(─‿─)

Negative integers are used to represent values below zero, and in this context, "-50" represents a depth of 50 feet below the sea level.

In the context of sea level and vertical position, we often use positive and negative numbers to represent positions above or below a reference point, which is usually considered to be sea level.

When we say the diver is 50 feet below sea level, it means the diver is at a depth of 50 feet under the surface of the sea. In this case, we use negative numbers to represent positions below sea level.

So, if we consider sea level as the reference point (zero level), the number line extends in both positive and negative directions. Positive numbers represent positions above sea level, and negative numbers represent positions below sea level.

Since the diver is 50 feet below sea level, we represent this as -50. The negative sign indicates that the diver is below the reference point (sea level), and the absolute value of 50 represents the depth of 50 feet.

Therefore, the integer -50 correctly represents the situation of a diver being 50 feet below sea level.

To know more about sea level.

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Answer:

12×0.25 is definitely right

×0.25 is another way of finding a quarter of something. I looked at the other answers and I think this one is the only correct one

Answer:

30.96 m^2

Step-by-step explanation:

Side length of the square is also the diameter of the semicircle so:

r = 0.5 * 12 m = 6 m

Since you want the area of the shaded area, you have to subtract the area of both semi circles from the area of the square:

Square Area - Semi Circle Area - Semi Circle Area = Shaded Region Area

(12 m * 12 m) - (0.5 * 3.14 * 6^2 m) - (0.5 * 3.14 * 6^2 m)

= 144 - 56.52 - 56.52

= 30.96 m^2

Answer:

C=D=58

B=A=35

AEC=BED=180-(58+35)

=87

AED=BEC=(360-174)/2

=93

AED=93

Answer:

only if you help me i can help you if you help me

Step-by-step explanation:

Answer:

f(x) = 1/2x + 2

Step-by-step explanation:

...........

Answer:

C

Step-by-step explanation:

I think so

Answer:

When y = 4, x is equal to 39

Step-by-step explanation:

The given parameters are;

x = a + b + 4

a ∝ 1/y²

b ∝ 1/(1/y) = y

When y = 2, x = 18

When y = 1, x = -3

Therefore, we have;

a·y² = j

a = j/y²

b ∝ 1/(1/y)

∴ b ∝ y

b = k·y

When y = 2, x = 18, we have;

a = j/y² = j/2² = j/4

b = k·y = k·2

x = a + b + 4

∴ 18 = j/4 + k·2 + 4...(1)

When y = 1, x = -3, we have;

a = j/y² = j/1² = j

b = k·y = k·1 = k

x = a + b + 4

∴ -3 = j + k + 4...(2)

Making 'j', the subject of equation (1) and (2) gives;

From equation (1), we have;

18 = j/4 + k·2 + 4

∴ j = (18 - 4 - k·2) × 4 = 56 - 8·k

From equation (2), we have;

-3 = j + k + 4

∴ j = -3 - 4 - k = -7 - k

Equating the two values of 'j', gives;

56 - 8·k = -7 - k

56 + 7 = 8·k - k

63 = 7·k

k = 63/7 = 9

k = 9

From equation (2), we get;

-3 = j + k + 4

k = 9

∴ -3 = j + 9 + 4

j = -3 - 9 - 4 = -16

j = -16

When y = 4, we get;

x = a + b + 4

a = j/y²

b = k·y

∴ x = j/y² + k·y + 4

Plugging in the values of 'j', and 'k' and y = 4, gives;

x = (-16)/y² + 9·y + 4

∴ x = (-16)/4² + 9 × 4 + 4 = 39

x = 39

Therefore;

When y = 4, x = 39.

Answer:

3. a =42

Step-by-step explanation:

2 ways you can go about this, you can either multiply 7x6 to get 42 as your answer. Or you can go through the options and divide each by 6 until eventually you'll find the one option that equals 7 which you would find is choice 3 a = 42

Answer:

3) x = -4

4) x = 9

Step-by-step explanation:

3) (x+15)+(x+16) = 23

2x+31 = 23

2x = -8

x = -4

4) (2x-12)+1 = (x-2)

2x-11 = x-2

x = 9

Answer:

x = 11/3 = 3 2/3

y = 13/3 = 4 1/3

Step-by-step explanation:

Here, we want to solve the system of equations simultaneously

x + y = 8

2x -3 = y

From the second equation, we have an equation for y

we can simply proceed to substitute this into the first equation

x + 2x - 3 = 8

3x - 3 = 8

3x = 8 + 3

3x = 11

x = 11/3

Recall;

y = 2x - 3

y = 2(11/3) - 3

y = 22/3 - 3

y = (22-3(3))/3

y = (22-9)/3 = 13/3