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skad [1K]
3 years ago
13

The scores for a certain test of intelligence are normally distributed with mean 85 and standard deviation 11. Find the 90th per

centile of these scores.
Mathematics
1 answer:
jonny [76]3 years ago
5 0

Answer:

99.1 is the 90th percentile of these scores.

Step-by-step explanation:

We are given the following information in the question:

Mean, μ = 85

Standard Deviation, σ = 11

We are given that the distribution of score is a bell shaped distribution that is a normal distribution.

Formula:

z_{score} = \displaystyle\frac{x-\mu}{\sigma}

We have to find the value of x such that the probability is 0.90

P( X < x) = P( z < \displaystyle\frac{x - 85}{11})=0.90  

Calculation the value from standard normal z table, we have,  

P(z \leq 1.282) = 0.90

Putting values, we get,

\displaystyle\frac{x - 85}{11} = 1.282\\\\x = 99.1

Thus, 99.1 is the 90th percentile of these scores.

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A local bakery sells cookies for 5.50 per pound and brownies for 7.50
uysha [10]

Answer:

I may be wrong but i think the answer is D

Step-by-step explanation:

We know that y=10, so if we were to multiply 10 by 7.50, it would be 75, not 63, so A and B wouldn't be correct. and we don't know the value of x, so I think D is the best answer.

6 0
3 years ago
Solve 7x + 6 &lt; 3(x - 2).
sasho [114]
7x+6=3x-6
    +6       +6
7x+12=3x
-3x       -3x
 4x+12=0
-4x         -4x
 divide both sides by -4 but you have to flip the sign.   
-3>x
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8 0
3 years ago
What is the slope of the line with the equation -7x + 4y = -8
lys-0071 [83]

Answer:

1 3/4 or 7/4 or 1.75

Step-by-step explanation:

4 0
3 years ago
I need help with this question I will give brainliest
guajiro [1.7K]

Answer:

No

Step-by-step explanation:

In order for there to be a right triangle formed, this must satisfy pythagoran's theorm thingy:

a^2+b^2=c^2

7^2+15^2=274

22^2= 484

since 274 isnt equal to 484

There is not a right triangle formed here

7 0
2 years ago
Need help with this pls show work
Gemiola [76]

Answer:

Ron got 3 additional toppings

Step-by-step explanation:

Lets call the amount of toppings that Ron got t. With this, we can set up the following equation:

8.95+0.65t=10.90

Subtract 8.95 from both sides:

0.65t=1.95

Divide both sides by 0.65:

t=3

Hope this helps!

6 0
3 years ago
Read 2 more answers
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