Assume that adults have IQ scores that are normally distributed with a mean of 98.8 and a standard deviation 17.1. Find the first quartile Q1, which is the IQ score separating the bottom 25% from the top 75%. (Hint: Draw a graph.)

Using the normal distribution, it is found that the IQ score separating the bottom 25% from the top 75% is of 87.

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Normal Probability Distribution

Problems of normal distributions can be solved using the z-score formula, which  in a set with mean and standard deviation , is given by:

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The IQ score is 87.

A similar problem is given at link

The  IQ score separating the bottom 25% from the top 75%. is 87.3

Step-by-step explanation:

Given that adults have IQ scores that are normally distributed with a mean of 98.8 and a standard deviation 17.1.

To find the first quartile, we calculate X such that P(X<z)=0.25.

From the normal distribution table the The z-value that corresponds to an area of 0.25 is z=-0.675

We  use the formula:

We substitute to get:

This implies that:

Solve for x to get:

X=87.2575

step-by-step explanation:

given perimeter: 28cm

length: 9cm

atp,

2(l+w)=p of the reactangle

2(9+x)=28

18+2x=28

2x=28-18

x=10/2

x=5

therefore width is 5 cm

the simplified form is

step-by-step explanation:

we want to simplify the expression,

let us change the middle bar to a normal division sign to obtain,

we multiply the first fraction by the reciprocal of the second fraction to obtain,

we factor to obtain,

we cancel the common factors to get,

we simplify to get,

the correct answer is b