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3 years ago

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When Mrs. Myles gave a test, the scores were normally distributed with a mean of 72 and a standard deviation of 8. This means th

at 95% of her students scored between which two scores?

2 answers:

Nimfa-mama [501]3 years ago

8 0

Given a standardized test with a mean score of 78 and a standard deviation of 5.9, a student who scored in the 60th percentile could have a score of:
a. 84
b. 72
c. 79
d. 76
the answer is c

astra-53 [7]3 years ago

7 0

Answer:

The score of Mr.Myles is between 56 and 88.

Step-by-step explanation:

Given : When Mrs. Myles gave a test, the scores were normally distributed with a mean of 72 and a standard deviation of 8.

To find : The class interval at 95% of her students scored between which two scores?

Solution :

We have given,

Mean $\mu=72$

Standard deviation $\sigma=8$

The class interval at 95% is given by

$\mu-2\sigma\leq CI\leq \mu+2\sigma$

Substitute the values in the formula,

$72-2(8)\leq CI\leq 72+2(8)$

$72-16\leq CI\leq 72+16$

$56\leq CI\leq 88$

Therefore, The score of Mr.Myles is between 56 and 88.

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How do I write this fraction as a decimal 14 3/5

Softa [21]

we have

$14 \frac{3}{5}$

This is a mixed number

we know that

A mixed number is a combination of a whole number and a fraction.

So

$14 \frac{3}{5}$ is equal to

$14 +\frac{3}{5}$

where

$14$ is the whole number

$\frac{3}{5}$ is the fraction

$\frac{3}{5}=0.60$

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therefore

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$14.60$

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2 years ago

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Jerry has a miniature model of a boat. He knows that the boat is 3 3/4 inches wide and 5 1/2 inches long. What is the actual len

FromTheMoon [43]

Width of the miniature model = $3\frac{3}{4}$ inches

Length of the miniature model = $5\frac{1}{2}$ inches

The actual width of the boat = 15 feet

Let us find the actual length of the boat.

Write it in a proportion form.

width of model : length of model : : width of actual : length of actual

$$\Rightarrow 3\frac{3}{4}:5\frac{1}{2}::15:x$

$$\Rightarrow\frac{15}{4}:\frac{11}{2}::15:x$

$$\Rightarrow\frac{\frac{15}{4}}{\frac{11}{2}} =\frac{15}{x}$

Do cross multiplication.

$$\Rightarrow{\frac{15}{4}x =15\times\frac{11}{2}$

$$\Rightarrow{\frac{15}{4}x =\frac{165}{2}$

$$\Rightarrow x =\frac{165}{2}\times{\frac{4}{15}$

⇒ x = 22

Hence the actual length of the boat is 22 feet.

6 0

3 years ago

In the picture below, ABCD is a rectangle. If the area of triangle ABE is 40, what is the area of the triangle?

MariettaO [177]

Area of the rectangle: 112

Step-by-step explanation:

Picture is missing: find it in attachment.

The area of a triangle is given by

$A=\frac{1}{2}bh$

where

b is the length of the base

h is the height

For triangle ABE, we know that

A = 40 (area)

h = 8 (height)

So we can find the length of the base AE:

$AE=b=\frac{2A}{h}=\frac{2(40)}{8}=10$

Now we observe that the base of the rectangle, AD, is the sum of AE and DE, therefore:

$AD=AE+DE=10+4=14$

We also know the height of the rectangle AB is 8, and that the area of a rectangle is

$A=bh$

where b is the base and h the height. Therefore, the area of this rectangle is

$A=bh=(AD)(AB)=(14)(8)=112$

Learn more about area of figures:

brainly.com/question/4599754

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#LearnwithBrainly

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3 years ago

Explain how you would use fraction bars to find the quotient of 10/12 ÷ 4/6. What is the quotient?

mylen [45]

(10/12) / (4/6)...when dividing with fractions, flip what u r dividing by, then multiply

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4 0

2 years ago

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What is the area of the sector ?

worty [1.4K]

They forget to say "not to scale". I'm guessing this is trig because I don't see another way to do it.

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$x^2 = 9^2 + 9^2 - 2(9)(9) \cos B$

$x^2 = 162 - 162 \cos B$

$\cos B = \dfrac{162 - x^2}{162} = 1 - \dfrac{x^2}{162}$

$\cos B = 1 - \dfrac{34 - 30\cos 81^\circ}{162}$

$B = \arccos \left(1 - \dfrac{34 - 30\cos 81^\circ }{162} \right)$

The area of the circle is the fraction given by the angle,

$A = \dfrac{B}{360^\circ} \pi r ^2$

$A \approx \dfrac{ \arccos \left(1 - \dfrac{34 - 30\cos 81^\circ}{162} \right) }{360} (3.142)9^2$

$A\approx 24.7474332960707$

Answer: 24.7 sq cm

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2 years ago