Question

2.

In the following questions, assume you have a normal distribution.

The average score on a mathematics test is 36. The standard deviation is 4.

What percentage can be expected to score between 33 and 35?

3. In the following questions, assume you have a normal distribution.

The average score on a mathematics test is 36. The standard deviation is 4.

What score falls at the 50th percentile?

4. Given, an IQ test with:

u= 100

o= 16

What percent of IQ scores will fall above a z-score of -1.6?

5. Given, an IQ test with:

u= 100

o= 16

What proportion of scores falls between an IQ of 90 and an IQ of 103?

6. Given, an IQ test with:

u= 100

o= 16

What IQ falls at the 28^th percentile?

7.

A sample of 9 drivers in Ohio reported the number of trips they took outside the county from where they lived. The data is reproduced below.

Compute the standard deviation of the distribution.

What IQ falls at the 28^th percentile?

7.

A sample of 9 drivers in Ohio reported the number of trips they took outside the county from where they lived. The data is reproduced below.

Compute the IQR of the distribution.

8. Statistic is related to parameter as:

9.

If

and N = 5, then the sum of X = ______

Answer 1

2) Let the random variable representing maths scoring be denoted by X.

So, X ~ N(36, 42)

P(33 < X < 35)

= P(X < 35) - P(X < 33)

= P(Z < (35-36)/4) - P(Z < (33-36)/4)

= P(Z < -0.25) - P(Z < -0.75)

= 0.401 - 0.227

= 0.174.

3) The score which is the 50th percentile =

Let the 50th percentile score be denoted by x.

P(X < x) = 0.5

P(X < (x-36)/4) = 0.5

(x-36)/4 = 0

x = 36

So, the score which falls at the 50th percentile is 36.

PLEASE SEND REST OF THE QUESTIONS AS SEPARATE QUESTIONS.