The ages of students at a university are normally distributed with a mean of 21. What percentage of the student body is at least 21 years old? a. 50% b. It could be any value, depending on the magnitude of the standard deviation. c. 1.96% d. 21%

Answers

Answer 1

Answer:

50%

Step-by-step explanation:

Recall : When given a normal or Symmetric distribution, the mean of the distribution is at the centre with 0.5 or 50% of the distribution to either side (right and left) of the distribution.

Hence, if the mean = 21 ; then the percentage of student body with atleast 21 years is the percentage to the left of the distribution, which is 50%.

Therefore, P(x ≤ 21) = 0.5 = 50%


Related Questions

A sample of radium has a weight of 1.5 mg and decays
by half every 6 years. Circle all of the following
functions that correctly model the amount of radium
f(t) in mg remaining after t years

Answers

Answer: [tex](b)[/tex]

Step-by-step explanation:

Given

Initial mass of radium is [tex]A_o=1.5\ mg[/tex]

It decays by half every 6 years i.e. [tex]T_{\frac{1}{2}}=6[/tex]

For radioactive decay, sample at any time is given by

[tex]\Rightarrow A=A_o2^{-\dfrac{t}{T_{\frac{1}{2}}}}[/tex]

Insert the values

[tex]\Rightarrow A=1.5\cdot 2^{\dfrac{-t}{6}}\\\\\Rightarrow A=1.5\cdot \left(\dfrac{1}{2}\right)^{\dfrac{-t}{6}}\\\\\Rightarrow A=1.5\cdot (0.5)^{\dfrac{t}{6}}[/tex]

Thus, option  (b) is correct.

please help. giving brainliest. 10 points

Answers

Answer:

for B based on the information givin the answer would be 8 4/7

hope this helps

Answer:

60/7 or 8 4/7

Step-by-step explanation:

Take the length of one of your rods and multiply by 15.

4/7 x 15/1 = 60/7 or 8 4/7

A teacher is comparing the quarter grades between two of her classes. She takes a random sample of 8 students from each class and lists the grades as shown. Find the mean for Class A.
Class A: 80, 83, 74, 91, 76, 87, 93, 72
Class B: 90, 75, 82, 86, 73, 85, 79, 94

Answers

The mean for class A is 82

Every given minute an ameba is equally likely to do one of 3 things: (1) Die (2) Divide into two (3) Stay the same. If the ameba divides, each of the two cells will continue the above cycle independently. What is the probability that the ameba colony generated from a single cell will eventually die out.

Required:
What is the probability that the ameba colony generated from a single cell will eventually die out?

Answers

Answer:

1

Step-by-step explanation:

we have the probability of dyng = 1.3

we have probability of ying =

p0 = p1 = p2 = p3 = 1/3

d = dying

[tex]d=\frac{1}{3} (1+d+d2)[/tex]

we cross multiply from here

3d = 1+d+d2

3d-d = 1+d2

2d = 1 + d2

(d-1)2 = 0

2d - 2 = 0

2d = 2

divide through by 2

d = 1

therefore there is a a confirmed probability that the ameba from a single cell is eventually going to die out.

Which of the folowing elements represent the whole? a. percentage b. base c. rate d. both a and b

Answers

Answer:

The answer is letter D

Explanation:

Hope it helps!

Answer:

D is the right answer

Explanation:

What is diameter d in meters if the distance around the track is 400 meters round your answer to the nearest tenth

Answers

The answer is 768 minutes away from the park I got it coming

Could someone please help me because I am rubbish at maths?
15% of £40​

Answers

the answer of this equation is 6

Answer:

£6.00

Step-by-step explanation:

15/100×40

=£6.00

does anyone know the answer to this i need help really bad!!!

Answers

Step-by-step explanation:

1/20.5 is yr ans

stay safe healthy and happy...

You work at a farm that wants to build three identical rectangular corrals in a row against the side of a barn using 112 ft of fencing. No fence is needed next to the barn itself. What dimensions (for each individual corral) will maximize the corral areas

Answers

Answer:

x  =  14 ft

y  =  56 ft

A(max corral)  =  784/3   =  261.33 ft²

Step-by-step explanation:

Let´s call y the side parallel to the barn, then only one y is going to be fenced.

If we are going to divide the area in three identical corrals we need 4 times x ( the other side perpendicular to the barn)

The perimeter of the rectangular area ( divide in three identical corrals)

112  =  y  +  4*x        or    y  =  112  -  4*x

A (r)  =  x*y

Area as a function of x  is

A(x) = x* ( 112  -  4*x)        A(x)   =  112*x  -  4*x²

Tacking derivatives on both sides of the equation

A´(x)  =  112  - 8*x       A´(x) = 0    112  -  8*x  =  0

x  =  112/8

x  =  14 ft

And  y  =  112  -  4*x     y  =  112 - 56

y  =  56 ft

A(max)  =  14 * 56  =  784 ft²

A(max corral)  =  784/3   =  261.33 ft²

How do we know the area is maximum, tacking the second derivative

A´´(x)  =  - 8     A´´(x) < 0

Then the function A(x) has a maximum at the point x = 14

Answer:

14ft by 18 2/3 ft

Step-by-step explanation:

which point is the vertex of the angle below

Answers

Answer:

The answer is K

Answer:

k

Step-by-step explanation:

3. Given the bar chart below,
(a) draw a frequency table from the graph.
(b) calculate the mean mark.
(c) what is the modal mark?
(d) find the median mark.
(e) if a student is selected at random, what is the probability that he/she scored
not less than 3 marks?
7
Frequent
п
0
-
0
3
5
N
6
6
Marks​

Answers

Answer: shehshywhwyw

Step-by-step explanation:

Trish and Aria are walking to raise money for the school library. Trish has walked 38 miles and walks 10 miles each week. Aria has walked 30 miles and walks 12 miles each week. Part A Drag numbers to complete the table to show the number of miles each girl has walked after each week. Numbers may be used once, more than once, or not at all. 5638907848426658 Name Start Week 1 Week 2 Week 3 Week 4 Week 5 Trish 68 88 Aria 30 54 Part B After how many weeks will Trish and Aria have walked the same number of miles? A. 2 weeks B. 3 weeks C. 4 weeks D. 5 weeks

Answers

Answer:

4 weeks

Step-by-step explanation:C. 5 weeks 90+48 138

88+40 138

Step-by-step explanation:

s

Which equation can be used to find the length of the missing side x?

Answers

It should be B. 7 sin 65, your answer would be 6.34415

The wheels on an adult sized 4-wheeler have a radius of 11 inches. What total distance will the wheels travel in one full rotation?

a
34.54 Inches

b
690.80 Inches

c
69.08 Inches

d
379.94 Inches

Answers

Answer:

C. 69.08 inches

Step-by-step explanation:

Find the distance the wheels will travel by finding the circumference of the wheel.

Use the circumference formula, C = 2[tex]\pi[/tex]r

Plug in 11 as r in the equation, and 3.14 as pi, then solve:

C = 2[tex]\pi[/tex]r

C = (2)(3.14)(11)

C = 69.08

So, the correct answer is C. 69.08 inches

Answer:

69.08 inches

Step-by-step explanation:

We can plug in the known value into the equation for circumference: [tex]C = 2\pi r[/tex]

Using 3.14 as [tex]\pi[/tex] we get:

[tex]C=69.08[/tex]

Now multiply the circumference by revolutions to get distance:

69.08 x 1 = 69.08

Note that the distance is in inches because the radius is in inches.

Solve.

(3- y) (2 y– 9)=0

(If there is more than one solution, separate them with commas.)

Answers

Answer:

3 , 9/2

Step-by-step explanation:

(3- y) (2 y– 9)=0

y=3 , y= 9/2

hope this helps! feel free to clarify

please help:) thank you

Answers

The answer is slope

HELP NEEDED!! QUESTION BELOW

Answers

Answer:

A

Step-by-step explanation:

The values will increase because the multiplier is greater than 1 (1.05).

please help me i really need help[ please

Answers

Answer:

70.69

Step-by-step explanation:

Area = [tex]\pi r (r + \sqrt{h^2+r^2} )[/tex]

Area = [tex]\pi (2.5) (2.5 + \sqrt{(6)^2+(2.5)^2} )[/tex]

Area = 70.68583471

Area = 70.69

help it's due tomorrow

Answers

answer: 72

wordswordswords

Ralph rolls a single die two times in a row. What is
the probability that he will roll a "three" both times?

Answers

Answer:

1/18 i think

Step-by-step explanation:

The probability of occurring 3 both times will be 1/36.

What is probability?

The probability of an event occurring is defined by probability.

Probability is also called the chance because if you flip a coin then the probability of coming head and tail is nothing but chances that either head will appear or not.

Do not take underestimate probability it has several uses in daily life whether forecasts or like that.

Probability of occurring 3 for the first time ⇒

number of outcomes/number of sample

Sample space {1,2,3,4,5,6} and outcome is 3

So,

P = 1/6

Probability of occurring 3 in second time⇒

number of outcomes/number of sample

Sample space {1,2,3,4,5,6} and outcome is 3

So,

P = 1/6

So,

Probability of occurring 3 both times = 1/6 × 1/6 = 1/36

Hence "The probability of occurring 3 both times will be 1/36".

For more information about the probability,

brainly.com/question/11234923

#SPJ2

Find the volume of the following cone. Area of base = 54 cm?

A) 180
B) 422.54
C) 513.33

Answers

Answer:

The volume of the cone is of 18h, in which h is the height of the cone.

Step-by-step explanation:

Volume of a cone:

The volume of a cone with base area [tex]A_b[/tex] and height h is given by:

[tex]V = \frac{A_bh}{3}[/tex]

Area of base = 54 cm

This means that [tex]A_b = 54[/tex] and thus:

[tex]V = \frac{54h}{3} = 18h[/tex]

The volume of the cone is of 18h, in which h is the height of the cone.

24 boys, 45 girls and 281 adults are the members of a badminton club.
50 more children join the club.
The number of girls is now 18% of the total number of members.
How many of the 50 children were boys?

Answers

24+45+281+50=400

(45+n/400)×100=18

45+n=18×4=72

n=72-45=27

50-27=23.

hope it's correct

23 of the 50 children added were boys. The answer is 23 boys

Given that 24 boys, 45 girls and 281 adults are the members of a badminton club.

Total number of people as members of badminton = 24 + 45 + 281 = 350

Percentage of girls = girls/total number x 100

% of girls = 45/350 x 100

% of girls = 12.9%

If 50 more children join the club, and the number of girls is now 18% of the total number of members. Then, the new total number of members will be

New total members = 350 + 50 = 400

Let g = new added girls from the children

Percentage of girls = girls/total number x 100

18 = (g + 45) / 400 x 100

18/100 =  (g + 45) / 400

cross multiply

0.18 x 400 = g + 45

72 = g + 45

make g the subject of formula

g = 72 - 45

g = 27 girls

To get the number of boys added, take 27 away from the 50 children. That is,

The number of boys added = 50 - 27 = 23 boys

Therefore, 23 of the 50 children added were boys

Learn more about arithmetic here: https://brainly.com/question/6561461

3. Solve for each power. 4 to the third power.

Answers

Answer:64

Step-by-step explanation:

Answer: 4 to the third power is represented as:

4^3 = 64

Hope this helped!

Plz help me well mark brainliest if correct..???

Answers

Answer:

23 students letter d ran the 50 yard dash

Answer:

18

Step-by-step explanation:

the time of the students:

23,24,24,28,32,32,34,35,37,37,38,41,43,56,55,55,56,61

there are 18 number so 18 students did it


What is the approximate area, rounded to the nearest square inch, of the frame only? Use 3.14 for 1

Answers

Answer:

Step-by-step explanation:

area of square=l^2

=12^2

=144 in.^2

hup meh please........​

Answers

Answer:

the answer is

A..0.248

HOPE IT HELPED

Plz help me well mark brainliest if correct.....


.......????

Answers

Answer:

C) The mean is about 100.

Step-by-step explanation:

We see that the best fit line (out of the options listed) would be y=100. The mean can also be algebraically calculated with the following equation:

Let [tex]a[/tex] be the mean (average) of the values:

[tex]a=\frac{75+50+100+125+75+150}{6}=95.8\overline{3}[/tex], which is closest to answer choice C) The mean is about 100.



You are the manager of a movie theater, and you are
analyzing attendance data from last weekend. On
Friday evening, 285 people come to see a new
animated movie. On Saturday evening, 355 people
come to see the same movie.
What is the approximate percent increase in
attendance?


Answers

Answer:

total number of people on Friday = 285

total number of people on Saturday = 355

total increment = 355-285 = 70

total increase percentage = 70÷285*100

= 24.56%

hope it helps!

The sum of a number and twenty-one is sixty-four.

What is the value of the number?

The number equals

Answers

Answer:

43

Step-by-step explanation:

64-21= 43 :))))) ez

Answer:

43

Step-by-step explanation:

I hope you pass your test!

EDG2021 <3

Plz help me well mark brainliest if correct

Answers

Answer:

387 is the answar because number of milk sold on monday is 212 and in tuesday 175

212+175=387

Answer:

387

Step-by-step explanation:

The addition of milk sold on monday with milk sold on tuesday

which is

212+175=387

Other Questions
Please help, dont understand NEED HELP DUE IN 2 MINUTES!!!!A food company is designing boxes for several products. Each box is a rectangular prism.The company also wants to offer a family size box of cereal. The family size box will be a dilation of the single serving 1.2-ounce box. It must contain 18.75 ounces of cereal. What scale factor does the company need to use for the family size box? Amelia needs to buy some cat food. At the nearest store, 2 bags of cat food cost $4.50. How much would Amelia spend on 6 bags of cat food? Writes a number sentence that is an example of the Distributive Property of Multiplication. Which shows Jamie's number sentence? Group of answer choices Your partner on a project wants to create a scientific informational report to explore what it was like to live in Japanese internment camps during World War II. Do you agree that this media form would work best for this particular history presentation Mr. Nieto has to pay an income tax of15% on earned wages of $25,500. Howmuch money will Mr. Nieto spend to pay theincome tax?F $382.50 H $3,825.00G $25,882.50 J $29,325.00 PLZ NEED HELP IS DUE TONIGHT !!!!!!!!!!!!!!!! what is the root word of "universal" PLEASE HELP FAST ITS DUE SOONNN What is the form of the word media? 1.Write short notes on the followinga) Population Statistics In the second paragraph, Morrie's dancing alone is a sign of his:A. loneliness.B. individuality.C. introversion.D. abnormality.Paragraph: He had always been a dancer, my old professor. The music didnt matter. Rock and roll, big band, the blues. He loved them all. He would close his eyes and with a blissful smile begin to move to his own sense of rhythm. It wasnt always pretty. But then, he didnt worry about a partner. Morrie danced by himself. bus has started to move fromthe rest with an acceleration of0.25 m/s. find its final velocity A red light flashes every 6 seconds.A yellow light flashes every 4 seconds.They both flash at the same time.After how many seconds will they next both flash at the same time? code 88304 assigned for specimens with low disease or malignancy probability is an example of a what pathology cade A 1.0 kg bottle of sodium carbonate (Na2CO3, 106.0 g/mol) is available to clean up 5.00 liters of spilled concentrated aqueous hydrochloric acid (9.75 M). Is this enough sodium carbonate to neutralize the acid according to the following reaction? 2 HCl (aq) + Na2CO3 (s) 2NaCl (aq) + CO2 (g) + H2O (l)(1) No, there is approximately 40% too small amount of sodium carbonate needed.(2) Yes, there is approximately 80% more than what is needed.(3) No, there is approximately 60% too small amount of sodium carbonate needed.(4) Yes, there is exactly enough sodium carbonate, but no excess.(5) No, there is approximately 20% too small amount of sodium carbonate needed. CD is the Diameter. The measure of Arc CD is llx Find the length of the radius in the circle Which statement best describes volcanoes?1. Volcanoes are difficult to predict because they dont erupt in a straight, orderly progression.2. Volcanoes are easy to monitor because every one follows the same order of events.3. Volcanoes usually occur in remote places, so they rarely affect humans.4. Volcanoes always cause typhoons before they erupt. if the sum of two consecutive odd number is 20 find the number SOMEONE HELP ME WITH 13 and 14 please!!!! Will makeU brainlist!!!