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3 years ago

The scores on a test given to all juniors in a school district are normally distributed with a mean of 75 and a standard deviati

on of 7.
Find the percent of juniors whose score is no more than 89.

The percent of juniors whose score is 89 or below is ___%

Mathematics

1 answer:

marta [7]3 years ago

3 0

$\mathbb P(X\le89)=\mathbb P\left(\dfrac{X-75}7\le\dfrac{89-75}7\right)=\mathbb P(Z\le2)\approx0.9773=97.73\%$

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7/12 divided by 2/5 I need help thanks and bye

Law Incorporation [45]

hey there!

7/12 divided by 2/5 is 7/30

first you have to find the reciprocal for 2 / 5 can do that by flipping 2 / 5 you'll then get 5 / 2 now the rest is simple all you have to do is multiply 7/12 by 2/5 so you multiply 7 by 2 and you get 14 that's your numerator 10 divide 12 by 5 and you'll get 60 so now you have 14 / 60 7 / 30 now you simplify and you get

I hope I helped please mark me brainliest

baiiiiiii

3 0

3 years ago

Find the number of the different ways, for 3 students to sit on 7 seats in one row.

qwelly [4]

Answer:

210

Step-by-step explanation:

Here comes the problem from Combination.

We are being asked to find the number of ways out in which 3 students may sit on 7 seats in a row. Please see that in this case the even can not be repeated.

Let us start with the student one. For him all the 7 seats are available to sit. Hence number of ways for him to sit = 7

Let us see the student second. For him there are only 6 seats available to sit as one seat has already been occupied. Hence number of ways for him to sit = 6

Let us see the student third. For him there are only 5 seats available to sit as two seat has already been occupied. Hence number of ways for him to sit = 5

Hence the total number of ways for three students to be seated will be

7 x 6 x 5

=210

3 0

3 years ago

Read 2 more answers

2x+y=8 y+3z=5 z+2w=1 5w+3x=9 Find the solution to each variable

morpeh [17]

Answer:

w = 0, x = 3, y = 2, z = 1

Step-by-step explanation:

You can use each equation to write an expression that will substitute into the next equation.

y = 8 -2x . . . . from the first equation

8 -2x + 3z = 5 . . . . . substituted into the second equation

z = (-3 +2x)/3 . . . . . solved for z

(-1 +2/3x) +2w = 1 . . . . . substituted into the third equation

w = (2 -2/3x)/2 . . . . . solved for w

5(1 -1/3x) +3x = 9 . . . . . substituted into the last equation

4/3x = 4 . . . . . simplified, 5 subtracted

x = 3 . . . . . . . . multiply by 3/4

w = 0 . . . . . . . .value of x substituted into equation for w

z = 1 . . . . . . . . value of x substituted into equation for z

y = 2 . . . . . . . .value of x substituted into equation for y

The solution is (w, x, y, z) = (0, 3, 2, 1).

4 0

3 years ago

A company uses the function C(x)=20.50+2000, where C is the cost and x is the number of units it produces, to determine its dail

Kipish [7]

You left it out, but I'm thinking that there must be an 'x' next to the '20.50' in the function. I'm so sure of it that I'll assume it, as I proceed to answer the question:

C(x) = 20.50x + 2,000

Subtract 2,000 from each side: C - 2,000 = 20.50 x

Divide each side by 20.50 : x = (C - 2,000) / 20.50

When C = $625,000 . . .

x = (625,000 - 2,000) / 20.50 = 623,000 / 20.50 = 30,390.2439

30,390 complete units are produced, and there are 5 bucks left over,
to split up among all the loyal employees who worked with such diligence and dedication to make it happen. The company's senior management will graciously add each worker's share to his gross pay before taxes for the second month following the close of the current quarter, with a photocopied note inserted in the pay envelope, expressing management's sincere thanks to everyone, an admonition not to spend it all in one place, and a reminder that no matter how many festivals to their god they need to go out to the desert to celebrate, their tally of bricks for the next quarter shall not be diminished.

6 0

3 years ago

Solve x^2-8x-9=0 using completing the square (show the work)

Elden [556K]

Answer: x=9,-1

Step-by-step explanation:

First, we are gonna start out with finding two numbers that multiply to equal -9 and add up to equal -8

Those numbers would be -9 & 1

-9+1=-8

-9x1=-9

Now we have

(x-9)(x+1)

x-9=0 x+1=0

+9 +9 -1 -1

x=9 x=-1

3 0

3 years ago