The average time it takes a group of students to complete a certain statistics exam is 55.6 minutes. The standard deviation is 9 minutes. Assume the exam completion times are normally distributed. If 40 randomly selected students take the exam, what is the probability that the mean completion time for the group will be less than 45 minutes?

Answer:

20%

Step-by-step explanation:

The ratio of 20 to 4 can be simplified to 5:1, by switching it around, we get 1/5. 1/5 as a percentage can be expressed as 20%

Answer:

20%

Step-by-step explanation:

Given the following question:

20% of 20

To find the answer we will use the formula to calculate percentages.

[tex]\frac{p\times n}{100}[/tex]
[tex]\frac{20\times20}{100}[/tex]
[tex]20\times20=400[/tex]
[tex]400\div100=4[/tex]
[tex]=4[/tex]

20% of 20 is 4, which means your answer is "20%."

Hope this helps.

Answer:

y-5=3/4(x-6)

Step-by-step explanation:

The picture you posted is a bit unclear and difficult to look at, but that's alright.

This is a simple question if you understand that the point slope for equation is: y-y1 = m(x-x1).

m is the slope and (x1,y1) is a point on the graph.

So, if you input the point (6,5) on the graph, it works.

You can double check with the other equations to see that they are all wrong!

Answer:

not congruent

Step-by-step explanation:

congruent is just a fancy way of saying the same in geometry. so to check if its congruent, see if all side lengths correspond to another side length on the other triangle. they do not, so they can't be congruent

hope this helped :)

Answer:

yes I know how to to multiple variables.

Answer:

8x + 12x = 180

x=9

Step-by-step explanation:

Answer:

x = 9

Step-by-step explanation:

8x + 12x = 180

20x = 180

x = 180/20

x = 9

Please mark me the brainliest!?!

B is true

Step-by-step explanation:

because no number with them to lines can be a negative

758

(if you don't have to use all the blocks)

757

750

708

754 etc

Answer:

c

Step-by-step explanation:

This series diverges by the limit test (some books may call it the nth term test).

Recall the limit test is the idea if the sequence doesn't converge to 0, then the series diverges.

In this case, the sequence converges to n/(7n) = 1/7 since all we are about are the leading terms when n gets very large.

After some very large n value, we're effectively adding on 1/7 or very close to it, each time. The infinite sum does not approach a fixed value. It keeps growing forever.

Answer:

D Because

Step-by-step explanation:

1/2 +1/2 is 1 so 1+1+3+4 is 9

HOPE THIS HELP! :)

Answer:

The first answer is D

the second answer is B

Step-by-step explanation:

The reason why the first answer is D is because in the problem it says at least twice as many seniors is travelling compared to the juniors and D is the only one that shows at least twice than as many juniors and it also it true in the equation 230>2y+x

The reason why the second answer is B is because both of the lines touch at the points (-2,1) which is the same points as B

Answer:

60/4

Step-by-step explanation:

Hope this helps.

The following histogram shows the relative frequencies of the height recorded to the nearest inch of population of women the mean of the population is 64.97 inches and the standard deviation is 2.66 inches

(a) Based on the histogram, what is the probability that the selected woman will have a height of at least 67 inches? Show your work

Answer:

0.22268

Step-by-step explanation:

z-score is z = (x-μ)/σ,

where x is the raw score

μ is the population mean

σ is the population standard deviation.

(a) Based on the histogram, what is the probability that the selected woman will have a height of at least 67 inches? Show your work

At least means equal to or greater than 67 inches

z = 67 - 64.97/2.66

z = 0.76316

P-value from Z-Table:

P(x<67) = 0.77732

P(x>67) = 1 - P(x<67) = 0.22268

The probability that the selected woman will have a height of at least 67 inches is 0.22268

Answer:

  5 17/18

Step-by-step explanation:

Your calculator can help with this.

__

The integer parts of the mixed numbers can be dealt with separately. The fractional parts are added and subtracted using a common denominator. Here, that denominator is the least common multiple (LCM) of 2, 3, and 9, so is 18.

  ((7 2/3) -(4 8/9)) +((5 2/3)) -(2 1/2))

  = (7 2/3) +(5 2/3) -((4 8/9) +(2 1/2))

  = 12 4/3 -(6 +8/9 +1/2)

  = 13 6/18 -(6 +16/18 +9/18)

  = 13 6/18 -(6 +25/18) = 13 6/18 -(7 7/18)

  = (13 -7) +(6/18 -7/18)

  = 6 -1/18

  = 5 17/18

__

Additional comment

Doing the math in the manner shown above means you can mostly do it without a calculator. If you like, you can convert all of the numbers to improper fractions, then add those. This often requires a calculator.

  = (138/18 -88/18) +(102/18 -45/18)

  = 50/18 +57/18

  = 107/18 = 5 17/18

Answer:

a₄ = 50

Step-by-step explanation:

work back from the seventh term a₇ using the reverse of the term to term rule , that is

divide by 2 then subtract 3

a₇ = 442

a₆ = 442 ÷ 2 - 3 = 221 - 3 = 218

a₅ = 218 ÷ 2 - 3 = 109 - 3 = 106

a₄ = 106 ÷ 2 - 3 = 53 - 3 = 50

Answer:

[tex]a_{4}=50[/tex]

Step-by-step explanation:

[tex]a_{4} = 50[/tex]

a₇ = 442

a₆ = 442 ÷ 2 - 3 = 221 - 3 = 218

a₅ = 218 ÷ 2 - 3 = 109 - 3 = 106

a₄ = 106 ÷ 2 - 3 = 53 - 3 = 50

The school is about 14.95 meters tall, and the mirror is 8.25 meters from the school.

Trigonometric ratio is used to show the relationship between the sides and angles of a right angled triangle.

Let Ф represent the angle Elijah makes with the ground, hence:

tanФ = 1.45/0.8

Ф = 61.11°

The angle of elevation to the building is 61.11°. Let h represent the height of the building.

tan(61.11°) = h/8.25

h = 14.95

The school is about 14.95 meters tall, and the mirror is 8.25 meters from the school.

Find out more on trigonometric ratio at: https://brainly.com/question/24349828

Answer:

i think its straight line

(a.) 0.09

equation:

f(x) = log(x)

rate of change:

[tex]\sf \rightarrow \sf \dfrac{y_2-y_1}{x_2-x_1}[/tex]

[tex]\sf \rightarrow \sf \dfrac{log(4) -log(6)}{4-6}[/tex]

[tex]\sf \rightarrow 0.088[/tex]

[tex]\sf \rightarrow 0.09[/tex]

Answer:

[tex]A.\: 0.09[/tex]

Step-by-step explanation:

Rate of Change is: [tex]\frac{y{_1-y{_2} } }{x_2-x_1}[/tex]

[tex]\frac{log(4)-log (6)}{4-6}[/tex]

[tex]0.088[/tex]

[tex]0.09[/tex]

In this question, to find the total height first, we must also take into consideration the acceleration due to gravity as well. To find the distance by which acceleration due to gravity pulls the ball down must know the Initial velocity.

In the answer key, it says that gravity changes the ball's height by a distance of -5t^2

Is initial velocity in this question 0 or 14m/s? Because if it is 14, then gravity should change the balls position by -(14+5t^2), not -5t^2, because if I remember correctly, the formula for finding distance is vt(initial velocity)+(1/2)at^2 ,and not just (1/2)at^2

Answer:

The 5 would be in the Thousands place

Step-by-step explanation:

Hope this helps any

Using it's concept, it is found that the domain of the function regarding the speed of the tidal wave is explained by:

[0, 4]: relating to the time of the tidal wave from it's origin in hours, restricted by the inability for the speed to be lees than zero.

It is the set that contains all possible input values for the function. In a graph, it is given by the x-values, that is, the horizontal axis values.

In this graph, the horizontal axis assumes values between 0 and 4, which is the time after the wave, and considering that the wave cannot be less than zero. Hence, the correct option is:

[0, 4]: relating to the time of the tidal wave from it's origin in hours, restricted by the inability for the speed to be lees than zero.

More can be learned about the domain of a function at https://brainly.com/question/25897115

Answer:

The probability that both balls in the box are red given that all three occasions a red ball is drawn from the box is [tex]\frac{4}{5}[/tex]

Step-by-step explanation:

Let RRR be the event in which red Balls are drawn from the box three times in succession

Let rr be the event that two red balls are placed in a box

Let rw be the event the first red ball was placed and then white ball was placed

Let wr be the event the first white ball was placed and then red ball was placed

Let ww be the event that two white balls are placed in a box

Now we know that :

[tex]P(rr)=P(rw)=P(wr)=P(ww)=\frac{1}{4}[/tex]

Probability of getting red Balls three times in succession given that both are placed red balls in box:

[tex]P(RRR|rr)=1[/tex]

Probability of getting red Balls three times in succession given that one ball is red and another is white in a box

[tex]P(RRR|wr)=P(RRR|rw)=\frac{1}{2^3}=\frac{1}{8}[/tex]

Probability of getting red Balls three times in succession given that both are placed white balls in box:

[tex]P(RRR|ww)=0[/tex]

Now we are supposed to find the probability that both balls in the box are red given that  all three occasions a red ball is drawn from the box i.e. P(rr|RRR)

So, we will use bayes theorem

[tex]P(rr|RRR)=\frac{P(RRR|rr) P(rr)}{P(RRR|rr) P(rr)+P(RRR|rw) P(rw)+P(RRR|wr) P(wr)+P(RRR|ww) P(ww)}\\P(rr|RRR)=\frac{1 \times \frac{1}{4}}{1 \times \frac{1}{4}+\frac{1}{8} \times \frac{1}{4}+\frac{1}{8} \times \frac{1}{4}+0 \times \frac{1}{4}}\\\\P(rr|RRR)=\frac{\frac{1}{4}}{\frac{5}{16}}\\\\P(rr|RRR)=\frac{4}{5}[/tex]

Hence the probability that both balls in the box are red given that all three occasions a red ball is drawn from the box is [tex]\frac{4}{5}[/tex]

Answer:

Step-by-step explanation:

8y8yy89y99u98u89y7t8y7i6u7i9jo

[tex]\textit{area of a sector of a circle}\\\\ A=\cfrac{\theta \pi r^2}{360}~~ \begin{cases} r=radius\\ \theta =\stackrel{degrees}{angle}\\[-0.5em] \hrulefill\\ r=20\\ \theta =90 \end{cases}\implies \begin{array}{llll} A=\cfrac{(90)\pi (20)^2}{360}\implies A=100\pi \\\\\\ A\approx 314.2 \end{array}[/tex]

Answer:

If the mass of one electron is 9.11 x 10-28 g, and you are looking for the mass of a mole of electrons, you need to understand Avogadro's number.  One mole is 6.02 x 1023 particles.  So you will have to multiply (6.02 x 1023) x (9.11 x 10-28 g) to get your answer of  5.48 x 10-4 grams (answer rounded to significant figures)

Step-by-step explanation:

1.2 x 10¹ times  greater is the mass of a carbon-12 atom than the mass of a neutron

A division is a process of splitting a specific amount into equal parts.

To find the ratio of the mass of a carbon-12 atom to the mass of a neutron, we can divide the mass of carbon-12 by the mass of a neutron:

(1.99×10⁻²³ grams) / (1.68×10⁻²⁴ grams)

= 11.8 grams

This means the mass of a carbon-12 atom is 11.8 times greater than the mass of a neutron. Written in standard notation and rounded to the nearest tenth, the answer is 1.2 x 10¹

Hence, 1.2 x 10¹ times  greater is the mass of a carbon-12 atom than the mass of a neutron

To learn more on Division click:

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Answer:22.25 oz

Step-by-step explanation:

1 batch of cookies = 8.9 oz

2.5 batches of cookies = x oz

cross multiply

1x=8.9(2.5)

x=22.25 oz

Answer:

The general term of the sequence is given by

T

n

=

a

n

2

+

b

n

+

c

The general term of the sequence is given by

T

n

=

a

n

2

+

b

n

+

c

Calculate a,b and c

Determine the 12th term of the sequence.

grade12 general-term sequence series

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answer comment

1 Answer

0

0

T3 - 6=6

T3=12

then T2-T1=4

6-T1=4

T1=2

T4-T3=8

T4-12=8

T4=20

Therefore terms= 2,6,12,20

1st difference= 4,6,8

2nd difference= 2,2,....

2a=2

a=1

3a+b=4

3(1) + b=4

b= 1

a+b+c= 2

c= 2-1- 1= 0

giving Tn= n^2 + n

T12 = 12^2 + 12 = 156

Answer: A

Step-by-step explanation: