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tangare [24]
2 years ago
9

Professor Hopkins is grading the final exam. She notices that the

Mathematics
1 answer:
NeX [460]2 years ago
8 0

Answer:

  143

Step-by-step explanation:

The interval of interest extends from the mean score (71) to 2 standard deviations above the mean (71+2(6) = 83). The area under the normal distribution curve in this interval can be found using a suitable table, probability app, spreadsheet, or web site. It can also be found using the "empirical rule", which tells you that the 95% of the area is within 2 standard deviations of the mean.

__

Since the curve is symmetrical, and we're only interested in the area above the mean, the empirical rule tells us that 95%/2 = 47.5% of the sample will be in the range of interest.

  0.475 × 300 = 142.5 ≈ 143

143 students will have a score between 71 and 83.

__

The attachment shows a calculator output for the same calculation. You will notice it is slightly different from the "empirical rule," which is only an approximation. Either way, we find 143 students have scores in the range.

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Norma's retirement party will cost $24 if she invites 12 guests. If there are 13 guests, how much will Norma's retirement party
blagie [28]

Answer:

If there are 13 guests, it would cost Norma $26

Step-by-step explanation:

Since 12 guest equals 24 dollars all you have to do is divide 24/12 which would give you 2dollars. this means that she has to pay 2 dollars per guest. Multiply 13 becuase you want to know how much money it would cost with 13 guests and you get 26 dollars. Hope this helps.

8 0
3 years ago
Read 2 more answers
Solve the equation <img src="https://tex.z-dn.net/?f=8x%5E2%3D-36" id="TexFormula1" title="8x^2=-36" alt="8x^2=-36" align="absmi
chubhunter [2.5K]

Answer: 4(2x²+9) or i\frac{3\sqrt{2} }{2}

Step-by-step explanation:

To solve the equation by factoring, we want to set the equation to zero. In order to have the equation equal to zero, we want to add both sides by 36.

8x²=-36            [add both sides by 36]

8x²+36=0

When it comes to factoring, we want to pull out numbers or variables that are common in each term.

8x²+36=0         [take out a 4 in each term]

4(2x²+9)=0

It may seem that 2x²+9 can be factored further, it actually can't. This tells us that the factored form of the equation is 4(2x²+9)=0.

To solve the equation, we want to find the value of x. We already know the graph does not cross the x-axis because the y-intercept or vertex is (0,9).

4(2x²+9)=0       [divide both sides by 4]

2x²+9=0            [subtract both sides by 9]

2x²=-9               [divide both sides by 2]

x²=-9/2              [square root both sides]

x=\sqrt{-\frac{9}{2} } or x=i\frac{3\sqrt{2} }{2}

6 0
3 years ago
Read 2 more answers
Please help me complete this !! 12points
Svet_ta [14]

Answer:

1.

x1=1

x2=3

y1=5

y2=1

midpoint= (x1+x2/2, y1+y2/2)=(1+3/2,5+1/2)=(2,3)

2.

x1=2

x2=4

y1=4

y2=6

midpoint= (x1+x2/2, y1+y2/2)=(2+4/2,4+6/2)=(3,5)

3.

x1= -2

x2=4

y1=4

y2= -6

midpoint= (x1+x2/2, y1+y2/2)=(-2+4/2,4-6/2)=(1,-1)

4.

x1=0

x2=0

y1=3

y2=5

midpoint= (x1+x2/2, y1+y2/2)=(0/2,3+5/2)=(0,4)

5.

x1= -2

x2=2

y1= -6

y2=6

midpoint= (x1+x2/2, y1+y2/2)=(-2+2/2,-6+6/2)=(0,0)

6.

x1=1

x2=4

y1=4

y2=5

midpoint= (x1+x2/2, y1+y2/2)=(1+4/2,4+5/2)=(5/2,9/2)

7.

x1=-3

x2=-4

y1=5

y2=5

midpoint= (x1+x2/2, y1+y2/2)=(-3-4/2,5+5/2)=(-7/2,5)

8.

x1=5

x2= -4

y1=2

y2=6

midpoint= (x1+x2/2, y1+y2/2)=(5-4/2,2+6/2)=(1/2,4)

3 0
2 years ago
Fill in the integers -10, -8, -7, -6, -5, -4, -3, -2 and 0 into a magic square so that every row, column, and diagonal has a sum
ioda

-2 -10 -3

-7 0 -8

-6 -5 -4


That's the square, it was a fun puzzle :)

6 0
3 years ago
In the diagram AB =AD and
Greeley [361]

Answer:

AC ≅ AE

Step-by-step explanation:

According to the SAS Congruence Theorem, for two triangles to be considered equal or congruent, they both must have 2 corresponding sides that are of equal length, and 1 included corresponding angle that is of the same measure in both triangles.

Given that in ∆ABC and ∆ADE, AB ≅ AD, and <BAC ≅ DAE, <em>the additional information we need to prove that ∆ABC ≅ ADE is AC ≅ AE. </em>This will satisfy the SAS Congruence Theorem. As there would be 2 corresponding sides that are congruent, and 1 corresponding angle in both triangles that are congruent to each other.

8 0
3 years ago
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