Answer:
The proportion of children in this age range between 70 lbs and 85 lbs is of 0.9306.
Step-by-step explanation:
When the distribution is normal, we use 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.
A study suggested that children between the ages of 6 and 11 in the US have an average weightof 74 lbs, with a standard deviation of 2.7 lbs.
This means that 
What proportion of childrenin this age range between 70 lbs and 85 lbs.
This is the pvalue of Z when X = 85 subtracted by the pvalue of Z when X = 70. So
X = 85



has a pvalue of 1
X = 70



has a pvalue of 0.0694
1 - 0.0694 = 0.9306
The proportion of children in this age range between 70 lbs and 85 lbs is of 0.9306.
Let's say you have the equation
5x + 3y = 11
You are asked to test the ordered pair (1, 2) to see if it is a solution of the equation. A solution of the equation will make the equation a true statement. The ordered pair (1, 2) has 1 as its x-coordinate and 2 as its y-coordinate.
Substitute 1 for x and 2 for y in the equation. Then work it out to see if it is a true statement.
5x + 3y = 11
5(1) + 3(2) = 11
5 + 6 = 11
11 = 11
Since 11 = 11 is a true statement, the ordered pair (1, 3) is a solution of the equation.
Answer:
4x+7 = 5x-20
(reason: vertical angles are congruent; property used: distributive)
7 = 1x-20
1x = 7+20
1x = 27
x = 27
Answer:
1.2/15
2.4/11
3.1/12
4.2/23
5.3/10
6.51
7. 1
8.30
9.36/55
10.248/15
Step-by-step explanation:
hope it helps