Answer:
4.05% probability that a randomly selected adult has an IQ greater than 123.4.
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:

Probability that a randomly selected adult has an IQ greater than 123.4.
This is 1 subtracted by the pvalue of Z when X = 123.4. So



has a pvalue of 0.9595
1 - 0.9595 = 0.0405
4.05% probability that a randomly selected adult has an IQ greater than 123.4.
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Answer:
-4 < n ≤ 5
Step-by-step explanation:
Since the left inequality is an open circle and going to the right, the sign will be >
Since the right inequality sign is a closed circle and is going left, the sign would be ≤
The open circle ends at -4 so, n > -4
The closed circle ends at 5 so, n ≤ 5
You combine them and it looks like this:
-4 < n ≤ 5
Step-by-step explanation:
1. 3x + 4 = 19
3x = 15
x = 5
2. 7 + 2x = 15
2x = 8
x = 4