b) An achievement test was administered to a class of 20,000 students. The mean score was 80 and the standard deviation was 11. If Lingard scored 72 in the test, how many students did better than him

Answers

Answer 1

Answer: 15328

Step-by-step explanation:

The following can be deduced from the information given:

N = 20000

μ = 80

σ = 11

P(X>72) = 1 - P (X<72)

= 1 - P(Z < 72-80/11)

= 1 - P(Z < -8/11)

= 1 - P(Z < 0.7272)

= 1 - 0.2336 = 0.7664

Therefore, the number of students that were better than Lingard n(X > 72) will be:

= 20000 × 0.7664

= 15328


Related Questions

find the missing length indicated ​

Answers

Answer:  240

============================================================

Explanation:

Let y be the length of the vertical dashed red line in the drawing. More specifically, this dashed line is an altitude.

Along the top, the entire segment is 400 units long. The right piece is 144 units long, so the left piece is 400-144 = 256 units long.

The triangles are similar, allowing us to set up a proportion like so:

144/y = y/256

144*256 = y*y

36864 = y^2

y^2 = 36864

y = sqrt(36864)

y = 192

So this is the length of that vertical dashed red line.

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

Now shift your attention solely on the smaller triangle on the right side. It is a right triangle with legs 144 and 192. The hypotenuse is x.

We can use the pythagorean theorem to find x.

a^2 + b^2 = c^2

c = sqrt( a^2 + b^2 )

x = sqrt( 144^2 + 192^2 )

x = 240

240.

Let y be the length of the vertical dashed red line in the drawing. More specifically, this dashed line is an altitude.

Along the top, the entire segment is 400 units long. The right piece is 144 units long, so the left piece is 400-144 = 256 units long.

The triangles are similar, allowing us to set up a proportion like so:

144/y = y/256

144*256 = y*y

36864 = y^2

y^2 = 36864

y = sqrt(36864)

y = 192

So this is the length of that vertical dashed red line.

Now shift your attention solely to the smaller triangle on the right side. It is a right triangle with legs 144 and 192. The hypotenuse is x.

We can use the Pythagorean theorem to find x.

a^2 + b^2 = c^2

c = sqrt( a^2 + b^2 )

x = sqrt( 144^2 + 192^2 )

x = 240

What is Pythagorean Theorem?

Pythagorean theorem, the well-known geometric theorem that the sum of the squares on the legs of a right triangle is equal to the square on the hypotenuse (the side opposite the right angle)—or, in familiar algebraic notation, a2 + b2 = c2.

Learn more about the Pythagorean theorem at

https://brainly.com/question/343682

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1.) Three numbers form a geometric sequence whose common ratio is 0.5. If the first is reduced to 10 more than one quarter its value, the second decreased by 10, and the third increased by 10 more than twice its value, the resulting three numbers form an arithmetic sequence. Determine the original three numbers.

Answers

Let x be the first number in the sequence, so the first three numbers are

{x, 0.5x, 0.5²x}

Then

{x/4 + 10, 0.5x - 10, 2(0.5²x) + 10}

is arithmetic, so there is some constant c such that

0.5x - 10 = x/4 + 10 + c   ==>   x/2 - 10 = x/4 + 10 + c

2(0.5²x) + 10 = 0.5x - 10 + c   ==>   x/2 + 10 = x/2 - 10 + c

Solve the second equation for c :

x/2 + 10 = x/2 - 10 + c

c = 20

Substitute this into the first equation and solve for x :

x/2 - 10 = x/4 + 10 + 20

x/4 = 40

x = 160

Then the terms are

{160, 80, 40}

1101001÷11 i am really confused ​

Answers

Answer:

100091

Step-by-step explanation:

Write the equation, in slope intercept form of the line that has a slope of 2 and passes through the point (1,3)

Answers

Answer:

y = 2x + 1

Step-by-step explanation:

y = mx + c

m = slope = 2

y = 2x + c

sub x = 1, y = 3

3 = 2(1) + c

c = 1

An exponential function f(x) = ab^xpasses through the points (0, 2) and (3, 54). What are the values of a and
b?
a=
b =

Answers

Answers:

a = 2

b = 3

=======================================================

Explanation:

Plug in x = 0 and y = 2 to find that

y = a*b^x

2 = a*b^0

2 = a*1

2 = a

a = 2

Then plug in x = 3 and y = 54 to determine the value of b

y = a*b^x

y = 2*b^x

54 = 2*b^3

2b^3 = 54

b^3 = 54/2

b^3 = 27

b = (27)^(1/3)

b = 3

So we have y = a*b^x update to y = 2*3^x

Explain how the given graph is deceptive.

Complete the statements based on the bar graph.

By not starting the horizontal axis at 0, the
bar appears to be about one-fourth the height of the Pecan bar. The
bar appears to be about one-half the height of the Pecan bar. The
bar appears to be less than one-half the height of the Pecan bar. This misleads the viewer to
the number of each type of nut used

Ans:

Pine Nut

Walnut

Almond

Understimate

Answers

Answer:

In the picture below.

Step-by-step explanation:

From the commenter and answer above, confirmed on edge 2022.

Find the value of
[tex] {z}^9{ \times {z}^10 = {z}^x [/tex]

Answers

Step-by-step explanation:

Just use the Law of Indices.

Find the missing side or angle.
Round to the nearest tenth.
b=15 a=30 c=29 a=[?]. Acellus plz

Answers

Answer:

∠ A ≈ 79.0°

Step-by-step explanation:

Using the Cosine rule to find the angle

cosA = [tex]\frac{b^2+c^2-a^2}{2bc}[/tex]

        = [tex]\frac{15^2+29^2-30^2}{2(15)(29)}[/tex]

        = [tex]\frac{225+841-900}{870}[/tex]

        = [tex]\frac{166}{870}[/tex] , then

A = [tex]cos^{-1}[/tex] ([tex]\frac{166}{870}[/tex] ) ≈ 79.0° ( to the nearest tenth )

Derive the equation of the parabola with a focus at (2,4) and a directrix of y=8

Answers

Answer:

The equation of the parabola with a focus at (2,4) and a directrix of y=8 is,

48-8y=(x-2)²

Need help plz + will give brainlest

Thanks in advance

Answers

Answer:

it is  D.

Step-by-step explanation:

Triangles ABC and DEF are similar triangles. What are the lengths of the unknown sides?


A)

DF = 39 cm; DE = 15 cm

B)

DF = 48 cm; DE = 52 cm

C)

DF = 65 cm; DE = 25 cm

D)

DF = 52 cm; DE = 48 cm

Answers

Answer:

D)

DF = 52

AB = 48

Step-by-step explanation:

Use the two lengths of sides already given.

Divide to find the scale factor:

20 / 5 = 4

Scale factor: 4

Now multiply to find the unknown sides:

13 × 4  = 52

12 × 4 = 48

DF = 52

AB = 48

Hope this helped.

HELLO! CAN ANYBODY PLEASE GIVE THE ANSWERS TO THESEEEE! WOULD REALLY MEAN A LOT​

Answers

Well when the numbers combined they make bigger numbers but when you pull them apart they make smaller numbers

how many cubic meters of gravel are in the back of a full dump truck that measures 7m wide by 4m tall by 16m long​

Answers

Answer:

Step-by-step explanation:

Assuming the gravel reaches the top of the walls and no higher, the volume is 7×4×16 = 448 m³

Answer:

hello thereee

now vol of truck = l b h = 7 * 4 * 16 = 448 m^3

( 448m^3 is final ans...

glad for brainliest.... hope that helps <3

Ron has 22 coins with a total value of $ 1.85. The coins are nickels (5 cents) and dimes (10 cents). How many of each coin does he have?
Please help asap and thank you in advance!!

Answers

Answer:

18 dimes and 1 nickle

Step-by-step explanation:

This is because 18 time 10 is 180 and one of 5 add it and this is $1.85

Remeber a dollar is 100 cents

15 dimes, $1.50 and 7 nickels 35¢.


22 coins in total, $1.85 in total.

Hope this helps.

Find the missing length. The triangles are similar.

Answers

Answer:

Missing length = 12

Step-by-step explanation:

Let x represent the missing length.

Since the triangles are similar, ∆KLM ~ ∆KRS, therefore, the ratio of their corresponding side lengths would be the same. This implies that:

KL/KR = KM/KS

KL = 65

KR = 65 - 52

KR = 13

KM = 60

KS = x

Plug in the values

65/13 = 60/x

Cross multiply

65*x = 60*13

65x = 780

Divide both sides by 65

65x/65 = 780/65

x = 12

Which matrix equation represents the system of equations?

{-x+ 2y = 0
y= -2

Answers

We are given a system of equations,

[tex]\begin{cases}-x+2y=0\\y=-2\\ \end{cases}[/tex]

This will translate into a 2x2 matrix of coefficients (because 2 equations and 2 unknowns),

[tex]\begin{bmatrix}-1&2\\0&1\\ \end{bmatrix}[/tex]

The matrix will then be applied to the vector (lower dimensions on top),

[tex]\begin{bmatrix}x\\y\\ \end{bmatrix}[/tex]

And the result vector will be whats on the other side of equals sign,

[tex]\begin{bmatrix}0\\-2\\ \end{bmatrix}[/tex]

So to put everything together,

[tex]\begin{bmatrix}-1&2\\0&1\\ \end{bmatrix}\begin{bmatrix}x\\y\\ \end{bmatrix}=\begin{bmatrix}0\\-2\\ \end{bmatrix}[/tex]

Hope this helps :)

Complete the equation describing how x
and y are related.
х у
y = [ ? ]x
-2
-1
0
1
2
3
-6
-3
0
3
6
9
Enter the answer that
belongs in [?]

Answers

Answer:

y=3x

Step-by-step explanation:

-6/-2=3, -3/-1=3, 3/1=3. 6/2=3

Let two events A and B be independent. Knowing P(A)=0.8 and P(A+B)=0.93. Calculate the probability P(B).

Answers

Answer:

Hello,

P(B)=0.65

Step-by-step explanation:

If P(A+B) means P(A∪B)=0.93 then you may read below.

Let's say x=P(B)

A and B being independent, P(A∩B)=P(A)*P(B)=0.8*x

Since P(A∪B)=P(A)+P(x)-P(A∩B) ,

0.93=0.8+x-0.8*x

0.2*x=0.13

x=0.65

An article is marked to sell at a gain of 10%. If it be sold for Rs. 7.50 less there would be loss of 5%, find the cost price. ​

Answers

Answer:

750,. is answer

I hope it helps

You are dealt one card from a​ 52-card deck. Find the probability that you are not dealt a heart.

The probability is ___.
​(Type an integer or a fraction. Simplify your​ answer.)

Answers

Answer:

3/4

Step-by-step explanation:

There are 13 hearts in a 52 deck.

52-13=39

39/52=3/4

The probability that you are not dealt a heart from the deck of cards is 3/4.

What is the probability that you are not dealth with a heart?

Probability determines the chances that an event would occur. The probability the event occurs is 1 and the probability that the event does not occur is 0.

The probability that you are not dealth with a heart = 1 - (number of hearts / total number of cards)

1 - 13/52 = 39/52 =  3/4

To learn more about probability, please check: https://brainly.com/question/13234031

Find the length represented by x for each pair of similar triangles.
18cm, 9cm, and x
30cm, 15cm, and 25cm

Answers

Answer:

15 cm

Step-by-step explanation:

Since the traingles are similar, we can find the ratio between the side lengths, and it will be the same for each side.

We can use the side length 9 and 15 to find this ratio. 15/9=5/3. So, the ratio of a side length of the larger triangle to the smaller one is 5/3, so our equation becomes 5/3 = 25/x. Use any method you like to find that x=15.

Hope this helped,

~cloud

An insurance company offers its policyholders a number of different premium payment options. For a randomly selected policyholder, let X 5 the number of months between successive payments. The cdf of X is as follows:

0 x<1
0.30 1< x <3
F(x)= 0.40 3< x <4
0.45 4< x <6
0.60 6< x <12
1 12< x

Required:
a. What is the pmf of x?
b. Using just the cdf, compute P(3< x <6)and P(4< x)

Answers

Answer:

(a)

[tex]\begin{array}{cccccc}x & {1} & {3} & {4} & {6} & {12} \ \\ P(x) & {0.30} & {0.10} & {0.05} & {0.15} & {0.40} \ \end{array}[/tex]

(b)

[tex]P(3 \le x \le 6) = 0.30[/tex]

[tex]P(4 \le x)=0.60[/tex]

Step-by-step explanation:

Given

[tex]F(x) = \left[\begin{array}{ccc}0& x<1 &\\0.30&1 \le x<3 &\\0.40&3 \le x < 4& &0.45 &4 \le x<6 &\\0.60 & 6 \le x < 12 & & 1 & 12 \le x\end{array}\right[/tex]

Solving (a): The pmf

This means that we list out the probability of each value of x.

To do this, we simply subtract the current probability value from the next.

So, we have:

[tex]\begin{array}{cccccc}x & {1} & {3} & {4} & {6} & {12} \ \\ P(x) & {0.30} & {0.10} & {0.05} & {0.15} & {0.40} \ \end{array}[/tex]

The calculation is as follows:

[tex]0.30 - 0 = 0.30[/tex]

[tex]0.40 - 0.30 = 0.10[/tex]

[tex]0.45 - 0.40 = 0.05[/tex]

[tex]0.60 - 0.45 = 0.15[/tex]

[tex]1 - 0.60 = 0.40[/tex]

The x values are gotten by considering where the equality sign is in each range.

[tex]1 \le x < 3[/tex] means [tex]x = 1[/tex]

[tex]3 \le x < 4[/tex] means [tex]x = 3[/tex]

[tex]4 \le x < 6[/tex] means [tex]x=4[/tex]

[tex]6 \le x < 12[/tex] means [tex]x = 6[/tex]

[tex]12 \le x[/tex] means [tex]x = 12[/tex]

Solving (b):

[tex](i)\ P(3 \le x \le 6)[/tex]

This is calculated as:

[tex]P(3 \le x \le 6) = F(6) - F(3-)[/tex]

From the given function

[tex]F(6)= 0.60[/tex]

[tex]F(3-) = F(1) = 0.30[/tex]

So:

[tex]P(3 \le x \le 6) = 0.60 - 0.30[/tex]

[tex]P(3 \le x \le 6) = 0.30[/tex]

[tex](ii)\ P(4 \le x)[/tex]

This is calculated as:

[tex]P(4 \le x)=1 - F(4-)[/tex]

[tex]P(4 \le x)=1 - F(3)[/tex]

[tex]P(4 \le x)=1 - 0.40[/tex]

[tex]P(4 \le x)=0.60[/tex]

Find the sum of ∑4/k=1 (-4k)

Answers

Answer:

Hello,

Answer C: -40

Step-by-step explanation:

[tex]\displaystyle \sum_{k=1}^4\ (-4k)\\\\=-4*\sum_{k=1}^4\ k\\\\=-4*4*\dfrac{1+4}{2} \\\\=-4*5*2\\\\=-40\\[/tex]

What are the odds against picking a red marble from a bag of 10 green marbles, 10 yellow marbles, and 5 red marbles?

Answers

5 out of 25
pick the chance over
add all possibilities
P(red) = 5/25 = 1/5……………

find the sum of the given infinite geometric series​. NO LINKS OR ANSWERING QUESTIONS YOU DON'T KNOW

Answers

Answer:

320/3

Step-by-step explanation:

First find the common ratio

20/80 = 1/4

The sum of an infinite geometric series

sum = a1/ (1-r)  where a1 is the first term and r is the common ratio

         =80/ ( 1-1/4)

         = 80/(3/4)

        = 80 *4/3

      = 320/3

"What mathematical ideas are you curious to know more about as a result of takingthis class? Give one example of a question about the material that you'd like to explorefurther, and describe why this is an interesting question to you."

Answers

One mathematical idea I've always been curious about is "integration and derivation".

Integration is about assimilating different variables. Derivation is a mathematical process whereby a result is gotten from some initial assumptions.

Integration is used everyday in different aspects of our lives. For example, if a person is travelling from let's say point A to point B, the speed used by the person might vary but through integration, one can easily get the accurate speed.

Through the division of equations into smaller bits, once can use integration to get the answer that one seeks. Architect can use integration in building the right structures at the exact places where the structures fits.

Likewise derivatives can be used by businesses in assessing whether a profit or loss will be made for a particular transaction or sale of product.

You can read more on:

https://brainly.com/question/14295614

There’s a pic of the question, answer fasterrrrr pleaseeeee

Answers

Answer:

Sorry this is NWEA so I want you to try and figure it out on your own, hint: use subtraction.

Step-by-step explanation:

2.5 Hours, for number one.

B for the second one.

2. About how much is 123.1 do you weigh in pounds? Estimate if you don't know☺ Find an online converter and find out how many kilograms that is.​

Answers

Answer:

123.1 pounds is vary long, and I don't want to repeat, so 55.8372207 repeat.

Step-by-step explanation:

If you have any questions regarding my answer, tell me them in the comments, and I will come answer them for you. Have a good day.

if 25 liters of milk can make 8 tin of cheese how many liters of milk would b needed to make 11 tin of cheese? ​

Answers

Answer:

Step-by-step explanation:

34.375 Liters of milk make 11 tins of cheese. Assuming that milk is available in whole liters only, 35 Liters of milk are needed.

A bookkeeper needs to post the cost of the desk and the chair into his records. The cost of the desk is fives times the cost if the chair. The total cost of the desk and the chair is $720, what is the cost of the chair?

Answers

Answer:

120

Step-by-step explanation:

720÷6

why?

becoz 6= 1+5

1 is the cosy of the chair

5 is the cost of the desk

Other Questions
For many years, no one could communicate with people who had been born without hearing. These deaf people were not able to use a spoken language. But, beginning in the 1700s, the deaf were taught a special language. Using this language, they could share thoughts and ideas with others. The language they used was a language without sound. It was a sign language. How did this sign language work? The deaf were taught to make certain movements using their hands, faces, and bodies. These movements stood for things and ideas. People might move their forefingers across their lips. Thismeant, You are not telling the truth. They might tap their chins with three fingers. This meant my uncle. The deaf were also taught to use a finger alphabet. They used their fingers to make the letters of the alphabet. In this way, they spelled out words. Some deaf people could spell out words at a speed of 130 words per minute. Sign language and finger spelling are not used as much as they once were. Today, the deaf are taught to understand others by watching their lips. They are also taught how to speak.46. In the 1700s, the deaf were taught ____.A. to speak B. sign language C. to watch others D. move their fingers across their lips47. A tap on the chin with three fingers means____.A. hello. B. come on. C. I have a toothache. D. my uncle.48. How did sign language help the deaf? A. It helped them learn to read.B. The deaf could understand body movements made by normal people.C. It helped them communicate with other people. D. It helped them spell out words.49. Why are sign language and finger spelling not used as much as they used to?A. Because there are other ways to help the deaf communicate.B. Because it is difficult to use a finger alphabet.C. Because the speed of 130 words per minute is too difficult for most deaf people.D. Because sign language and finger spelling have no sound.50. What is the main idea of the passage youve read?A. How the deaf people communicate. B. Learning to spell.C. Teaching the deaf to speak. D. A comparison of sign language and finger spelling person's human rights should be violated.Based on these excerpts, on what principles would Gandhi and Mandela most likely agree? 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Be sure your response also includes information about the overlappingresponsibilities and relationships between FEMA and GOHSEP. (10 points) Do you know this for social studies Write any three importance of Measurement. Stay Safe,Stay Healthy and Stay Happy Please answer me this question fast, PLEASE Read the question and answer it there were 13 original states. there are now 50 . what fraction of the states are the original states Select all that apply.Which conditions relate to the research of van Helmont?plant mass related only to soilconclusions partly correctdemonstrated plant food from soilconducted around 1400 AD.plant mass related to H 20 A basket contains 11/12 pound of strawberries. One serving strawberries is 1/4 pound. How many servings of strawberries are in the basket? NO LINKS OR ANSWERING QUESTIONS YOU DON'T KNOW!!!! The product of two positive integer numbers is 70 and the sum of the same two numbers is 17. Find thenumbers. 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