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Dvinal [7]
3 years ago
9

The test results for a class with 24 students are normally distributed with a mean of 82 and a standard deviation of 8.9. What i

s the probability that a randomly chosen student earned a B or higher on the test (score of 80 or higher)?
Mathematics
1 answer:
alekssr [168]3 years ago
5 0

Answer:

The value is  P( X >  80 ) =  0.58901

Step-by-step explanation:

From the question we are told that

    The sample size is  n  =  24

    The mean is  \mu  =  82  

    The standard deviation is  \sigma  =  8.9

   

Generally the  probability that a randomly chosen student earned a B or higher on the test (score of 80 or higher )  is mathematically represented as

         P( X >  80 ) =  P( \frac{ X - \mu }{\sigma }  > \frac{ 80 - 82 }{ 8.9 } )

\frac{X -\mu}{\sigma }  =  Z (The  \ standardized \  value\  of  \ X )

 =>  P( X >  80 ) =  P(Z   > -0.225  )

From the z table  the area under the normal curve to the right  corresponding to    -0.225  is  

     P(Z   > -0.225  )   =   0.58901

=>   P( X >  80 ) =  0.58901

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irina1246 [14]

We have been given 4 choices. We are asked to choose the volume that could belong to a cube with a side length that is an integer.

We know that volume of a cube is cube of each side length.

To solve our given problem, we will take cube root of each given value. The cube root of which value will be an integer that will be our correct choice.

A. s^3=18

\sqrt[3]{s^3}=\sqrt[3]{18}

s=2.62074

Since cube root of 18 is not an integer, therefore, 18 is not a correct choice.

B. s^3=36

\sqrt[3]{s^3}=\sqrt[3]{36}

s=3.301927

Since cube root of 36 is not an integer, therefore, 36 is not a correct choice.

C. s^3=64

\sqrt[3]{s^3}=\sqrt[3]{64}

s=4

Since cube root of 64 is 4 and 4 is an integer, therefore, 64 is the correct choice.

D. s^3=100

\sqrt[3]{s^3}=\sqrt[3]{100}

s=4.641588

Since cube root of 100 is not an integer, therefore, 100 is not a correct choice.

5 0
3 years ago
Read 2 more answers
Answer for number 3
julia-pushkina [17]
36x^2-49
this closely matches the binomial formula of (a+b)*(a-b)=a^2-b^2
so we know:
a^2=36x^2
a=6x

b^2=49
b=7

so (a+b)*(a-b)=(6x+7)*(6x-7)=36x^2-49
4 0
3 years ago
-9x + (52x -3571) +357
nadya68 [22]
43x-3214 should be the answer
4 0
4 years ago
Nga
andrezito [222]

Answer:

Step-by-step explanation:

5 0
3 years ago
Help.me.please<br><br><br><br><br> please
neonofarm [45]

Well to be honest this question is really easy by what i understand, if you just need any one line to get a total of 21.

Obviously having three or four such lines might become a problem But not for this. You can obviously break down 21 in to three different categories or numbers like 1 7 and 13. And now put 13 in the middle and start from anywhere. You will get 21 along one such line.

3 0
3 years ago
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