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2 votes
Suppose a normal distribution has a mean of 20 and a standard deviation of four. A value of 26 is how many standard deviation's away from the mean?

2 Answers

3 votes

26=20+6=20+\frac64*4=20+1.5*4

which means 26 is 1.5 standard deviations away from the mean.
User Pjdupreez
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6.7k points
2 votes
Knowing that:
The standard score, or z-score, represents the number of Standard deviations that separate a random variable x from average.

Formula:


z = (value-average)/(standard\:deviation)

Data:
z = ?
value = 26
average = 20
standard deviation = 4

Solving:



z = (value-average)/(standard\:deviation)


z = (26-20)/(4)

z = (6)/(4)

\boxed{\boxed{z = 1.5}} \end{array}}\qquad\quad\checkmark

Answer:

\underline{26\:is\:1.5\:standard\:deviation\:in\:relation\:to\:the\:average.}
User Bernd Kampl
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6.3k points