The standard deviation of a probability distribution table is 26.6 and the mean is 674.0. during an event, you receive the result of 622.3. determine whether this value is considered usual or unusual and tell why.

usual, because the result is within the range of the minimum and maximum usual values.
usual, because the result is less than the minimum usual value.
unusual, because the result is within the range of the minimum and maximum usual values.
unusual, because the result is less than the minimum usual value.

Usual, because the result is within the range of the minimum and maximum usual values.

Step-by-step explanation:

When the z-scores is lower than -1.96 or higher than 1.96, they are considered  as unusual and interesting and they are statistically significant outliers.

The Z score can be calculated by,

where,

X = raw score = 622.3

μ = mean = 674

σ = standard deviation = 26.6

Putting tall the values,

As , so the result is usual, because it lies within the range of the minimum and maximum usual values.

Read more on -

the answer is (-8,-5)

step-by-step explanation:

the endpoint to midpoint is half the length. the length is (-2,-1) so when you are at the midpoint just add it to it to find your answer -6+(-2)= -8 and -4+(-1)=-5 so (-8,-5)