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A given data value has a Z-value equal to 1.2. Assuming a normal (i.e., symmetrical) continuous probability distribution, how many standard deviations is the data value from the mean?

User Blue
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2 Answers

5 votes

Answer:

1.2

Explanation:

the number of standard deviations that the data value is away from the mean is 1.2 standard deviations, and thats because the units of the Z values are standard deviations.

if you remember the Z value formula is (X - mean) / SD, you are subtracting the X (data value) from the mean, and then dividing by standard deviations to get the number of standard deviations that the data value is away from the mean

if the Z value is positive that means that the data value is above from the mean.

if the Z value is negative that means that the data value is below from the mean

User Hamed Naeemaei
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5.7k points
6 votes

Answer: 1.2

Explanation:

Let x be a random data value that follows a normal distribution.

The formula to find the z-value :-


z=(x-\mu)/(\sigma), where
\mu is the population mean and
\sigma is the standard deviation.

Given : A data value has a Z-value equal to 1.2.

Then, we have


z=(x-\mu)/(\sigma)\\\\\Rightarrow\ 1.2=(x-\mu)/(\sigma)\\\\\Rightarrow\ x-\mu=1.2\sigma\\\\\Rightarrow\ x=\mu+1.2\sigma

Hence, the data value is 1.2 standard deviations from the mean.

User Dmnc
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