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A data set of values has a mean of 45 and standard deviation of 5. The z-score for a point A is 0. The z-score for a point B is0.2. What are the values of point A and point B?

User Olivier P
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2 Answers

14 votes
14 votes
Point B Is 36.

hope this helped
User Kurniawan Prasetyo
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3.2k points
28 votes
28 votes

Solution:

Given;

A data set of values has a mean of 45 and standard deviation of 5.

The z-score for a point A is 0. The z-score for a point B is 0.2.

To find the values of A and B, we will apply the z-score formula, which is


\begin{gathered} z=(x-\mu)/(\sigma) \\ Where\text{ } \\ x\text{ is the observed value} \\ \mu\text{ is the mean} \\ \sigma\text{ is the standard deviation} \end{gathered}

Where


\begin{gathered} \mu=45 \\ \sigma=5 \end{gathered}

For the value of point A,

Where, z = 0 for point A


\begin{gathered} z=(x-\mu)/(\sigma) \\ 0=(x-45)/(5) \\ Crossmultiply \\ 5(0)=x-45 \\ 0=x-45 \\ x=45 \end{gathered}

Hence, the value of point A is 45

For the value of point B,

Where, z = 0.2 for point B


\begin{gathered} z=(x-\mu)/(\sigma) \\ 0.2=(x-45)/(5) \\ Crossmultiply \\ 0.2(5)=x-45 \\ 1=x-45 \\ Collect\text{ like terms} \\ x=1+45=46 \\ x=46 \end{gathered}

Hence, the value of point B is 46

User Lohith MV
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2.8k points