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2 years ago

14

the mean of normally distributed test scores is 80 and the standard division is 5. If there are 186 test scores in the data samp

le, how many of them were in the 75 to 80 range?

1 answer:

Marizza181 [45]2 years ago

5 0

Answer:

63

Step-by-step explanation:

score 75 is one standard dev below the mean ====>to the mean encompasses approx 34% of scores

.34 * 186 = 63

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A kayaker can paddle 12 mi in 2 h moving with the river current. Paddling at the same pace, the trip back against takes 4 h. Ass

Firdavs [7]

Downstream DATA:
distance = 12 miles
time = 2 hours
rate = 12/2 = 6 mph
----------------
Upstream DATA:
distance = 12 miles
time = 4 hrs
rate = 12/4 = 3 mph
----
Equations:
Downstream: b + c = 6
Upstream::: b - c = 3
------
Add to get:
2b = 9
b = 4.5 mph (speed of the boat in still water.)
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Solve for "c":
b + c = 6
4.5 + c = 6
c = 1.5 mph (speed of the current)
The answer is 1.5 mph

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3 years ago

The isosceles trapezoid is part of an isosceles triangle with a 36° vertex angle. What is the measure of an acute base angle of

alexandr402 [8]

The answer is D) 72, 108

First you have to find out the measure of the two other angles in the triangle. Those two angles will be equivalent.

Because the sum of all three angles in a triangle is 180, you subtract 36 from it (180 - 36 = 144) then divide by 2 (144/2 = 72).

So, the two angles at the bottom of the triangle are each 72. Because those angles are supplementary to the angles at the top of the trapezoid, you subtract 72 from 180 (180 - 72 = 108).

108 + 108 = 216

The sum of all the angles in a trapezoid is 360, so subtract 216 from 360 (360 - 216 = 144) then divide by 2 (144/2 = 72)

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3 years ago

7. Which expression is the exponential form of 3√m

borishaifa [10]

Rewrite the rational (fraction) exponents using the formula ^n<span>√a^x= a x/n

3m 1/2 </span>

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3 years ago

Read 2 more answers

Help anyone can help me do the question 4,I will mark brainlest.

nasty-shy [4]

Answer:

Hello,

Step-by-step explanation:

$A=(1,2)\\B=(0,-1)\\\overrightarrow{AB}=((0,-1)-(1,2)=(-1,-3)\ ||\overrightarrow{AB}||^2=1+9=10\\\overrightarrow{BC}=((3,-2)-(0,-1)=(3,-1)\ ||\overrightarrow{BC}||^2=9+1=10\\\\Triangle\ is\ isosceles.\\\\\overrightarrow{AB}.\overrightarrow{BC}=(-1,-3)*\left[\begin{array}{c}3\\-1\end{array}\right] =-3+3=0\\\\Triangle \ is\ right.\\\\$

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3 years ago

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To make 4.5 cups of fruity granola, the recipe calls for 1.5 cups of raisins, 1 cup of granola, and 2 cups of blueberries. If yo

Levart [38]

Answer:

you need 6 cups of raisins, 4 cups of granola and 8 cups of blueberries.

Step-by-step explanation:

<u>Step 1: Find how much raisins are needed</u>

<em>For 4.5 cups of fruity granola, we need 1.5 cups of raisins</em>

<em>For 18 cups of fruity granola, we need y cups of raisins</em>

4.5 : 1.5

18 : y

<em>Cross multiply</em>

4.5y = 1.5 x 18

y = 27/4.5

y = 6 cups of raisins

<u>Step 2: Find how much granola is needed</u>

<em>For 4.5 cups of fruity granola, we need 1 cup of granola</em>

<em>For 18 cups of fruity granola, we need y cups of granola</em>

4.5 : 1

18 : y

<em>Cross multiply</em>

4.5y = 18

y = 4 cups of granola

<u>Step 3: Find how much blueberries are needed</u>

<em>For 4.5 cups of fruity granola, we need 2 cups of raisins</em>

<em>For 18 cups of fruity granola, we need y cups of blueberries</em>

4.5 : 2

18 : y

<em>Cross multiply</em>

4.5y = 2 x 18

y = 36/4.5

y = 8 cups of blueberries

Therefore, in order to make 18 cups of fruity granola, you need 6 cups of raisins, 4 cups of granola and 8 cups of blueberries.

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3 years ago