Question

In: Statistics and Probability

z-scores also follow a normal distribution with: µ=0 & σ=1 True or false?

z-scores also follow a normal distribution with: µ=0 & σ=1

True or false?

Solutions

Expert Solution

solution:

Yes, True : z-scores also follows a normal distribution with mean () = 0 and standard deviation () = 1

Reasoning:

Normal distribution: It is a probability distribution that is symmetric about mean, and showing the data near the mean are the most frequent in occurrence than the data far from the mean.It is also known as "Gaussian Distribution".The graph of the normal distribution will appear as 'bell curve'.

Properties of normal distribution:

-----> The distribution of curve is "Bell shaped"

-----> The curve is symmetric about mean. In normal distribution mean = mode = median

-----> The area under the curve is 1

standard normal distribution: Standard normal distribution is a special type of normal distribution.It is the distribution that occurs when the normal distribution has mean = 0 and standard deviation = 1.It has the same properties as the normal distribution.

Let X be the normal random variable and Z (z-scores) be the standard normal variable then the relation between

X and Z is

X = + Z()

For standard normal distribution,we know that

mean () = 0 and standard deviation () = 1

Then X = Z

which implies Z also follows normal distribution mean () = 0 and standard deviation () = 1.

Answer: True


Related Solutions

Let Z be a normal random variable with mean µ = 0 and standard deviation σ...
Let Z be a normal random variable with mean µ = 0 and standard deviation σ = 1, that is, Z ∼ N(0, 1). Find each of the following: (a) P(Z ≤ −1.13). (b) P(Z ≥ −2.18). (c) P(2.13 ≤ Z ≤ 2.57). (d) P(−2.3 ≤ Z ≤ −1.1). (e) P(0 ≤ Z ≤ 1.54). (f) P(−1.54 ≤ Z ≤ 1.54). (g) N(1.1243). (h) N(−1.1243).
Assume a normal distribution with μ = 0 and σ = 1, find the z-score(s) for...
Assume a normal distribution with μ = 0 and σ = 1, find the z-score(s) for each statement below: a) the area is 0.4 to the left of z b) the area is 0.18 to the right of z c) the middle area is 0.31 between −z and z __________________________ The heights of a certain population of corn plants follow a distribution with a mean of 137 cm and a standard deviation 23.19 cm. Find the raw scores for the...
For a normal distribution with a mean of µ = 150 and an SD of σ...
For a normal distribution with a mean of µ = 150 and an SD of σ = 15: 3. Find these probabilities: a. p (X > 150) b. p(X < 120) c. p(X < 170) d. p(130 < X < 175) A researcher wants to test her hypothesis that drinking caffeine while learning a new skill will aid in developing that skill. In order to test her hypotheses, she recruits a sample of 25 beginner piano students from a nearby...
Given a normal distribution with µ = 10 and σ = 2, find (a) the normal...
Given a normal distribution with µ = 10 and σ = 2, find (a) the normal curve area to the right of x = 6; (b) the normal curve area between x = 6 and x = 14; (c) the two values of x that contain the middle 75% of the normal curve area. please show all work if possible. Thank you
The tread life (x)  of tires follow  normal distribution with µ =  60,000 and σ= 6000 miles.  The manufacturer guarantees...
The tread life (x)  of tires follow  normal distribution with µ =  60,000 and σ= 6000 miles.  The manufacturer guarantees the tread life for the first 52,000 miles. (i) What proportion of tires last  at least 55,000 miles? (ii)  What proportion of the tires will need to be replaced under warranty? (iii)  If you buy 36 tires,  what is the probability that the  average life of your 36 tires will exceed  61,000?  (iv) The manufacturer is willing to replace only 3% of its tires under a warranty program involving tread life.  Find...
Let z denote a random variable having a normal distribution with μ = 0 and σ...
Let z denote a random variable having a normal distribution with μ = 0 and σ = 1. Determine each of the probabilities below. (Round all answers to four decimal places.) (a) P(z < 0.2) =   (b) P(z < -0.2) =   (c) P(0.40 < z < 0.86) =   (d) P(-0.86 < z < -0.40) =   (e) P(-0.40 < z < 0.86) =   (f) P(z > -1.24) =   (g) P(z < -1.5 or z > 2.50) =
Let z denote a random variable having a normal distribution with μ = 0 and σ...
Let z denote a random variable having a normal distribution with μ = 0 and σ = 1. Determine each of the following probabilities. (Round all answers to four decimal places.) (a) P(z < 0.1) = (b) P(z < −0.1) = (c) P(0.40 < z < 0.85) = (d) P(−0.85 < z < −0.40) = (e) P(−0.40 < z < 0.85) = (f) P(z > −1.25) = (g) P(z < −1.5 or z > 2.50) = Let z denote a...
Question 1 Given a normal distribution with µ=15 and σ = 5, what is the probability...
Question 1 Given a normal distribution with µ=15 and σ = 5, what is the probability that X>20 X<20 X<20 or X>20 INSTRUCTIONS: Show all your work as to how you have reached your answer. Please don’t simply state the results. Show graphs where necessary.
1. When the shape of the distribution of scores is normal, which of the follow is...
1. When the shape of the distribution of scores is normal, which of the follow is true: A.) mean < median < mode B.) mean = median = mode C.) mean > median > mode 2. When the score for the mean is significantly larger than the median score, you would expect the shape of the distribution of scores to be A.) need more information B.) positively skewed C.) negatively skewed D.) platykurtic E.) leptokurtic
A) If a normal distribution has a mean µ = 40 and a standard deviation σ...
A) If a normal distribution has a mean µ = 40 and a standard deviation σ = 2, what value of x would you expect to find 2 standard deviations below the mean B) If a normal distribution has a mean µ = 70 and a variance σ2 = 16, what value of x would you expect to find 2.5 standard deviations above the mean? C)If a sample yields a mean xmean = 44 and we know that the sum...
ADVERTISEMENT
ADVERTISEMENT
ADVERTISEMENT