IQ scores are measured with a test designed so that the mean is 116 and the standard deviation is 16. Consider the group of IQ scores that are unusual. What are the z scores that separate the unusual IQ scores from those that are usual? What are the IQ scores that separate the unusual IQ scores from those that are usual? (Consider a value to be unusual if its z score is less than minus2 or greater than 2.)

So the z-scores that separate the unusual IQ scores from those that are usual are Z = -2 and Z = 2.

The IQ scores that separate the unusual IQ scores from those that are usual are 84 and 148.

Step-by-step explanation:

Problems of normally distributed samples are solved using the z-score formula.

In a set with mean and standard deviation , the zscore of a measure X is given by:

The Z-score measures how many standard deviations the measure is from the mean. After finding the Z-score, we look at the z-score table and find the p-value associated with this z-score. This p-value is the probability that the value of the measure is smaller than X, that is, the percentile of X. Subtracting 1 by the pvalue, we get the probability that the value of the measure is greater than X.

In this question, we have that:

What are the z scores that separate the unusual IQ scores from those that are usual?

If Z<-2 or Z > 2, the IQ score is unusual.

So the z-scores that separate the unusual IQ scores from those that are usual are Z = -2 and Z = 2.

What are the IQ scores that separate the unusual IQ scores from those that are usual?

Those IQ scores are X when Z = -2 and X when Z = 2. So

Z = -2

Z = 2

The IQ scores that separate the unusual IQ scores from those that are usual are 84 and 148.

if the eqn of the parabola is f(x) = (x-4)(x+2), we need to mult. this out to find the coordinates of the vertex.

then f(x) = x^2 + 2x - 4x - 8, and f(x) = x^2 - 2x - 8.

one way in which you can find the vertex is to calculate x = -b / (2a).   here, that comes to

        )

x = = 1.   f(1) = 1^2 - 2(1) - 8 = - 9.   vertex is at (1, -9).

        2(1) 

find another point on the curve:   let x=0, for which y=-8.   then (0, -8) is on the curve.   plot the vertex and this point and draw a smooth parabola thru both.

hope this