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.
What was your question that was never answered?
Answer:
Step-by-step explanation:
2:3 is the correct answer
6-5x=3x
-5x-3=-6
-8=-6
x=-6/-8
= 3/4 or 0.75
Answer:
- 8
Step-by-step explanation:
To evaluate f(8) substitute x = 8 into f(x)
f(8) = - 2(8) + 9 = - 16 + 9 = - 7
Similarly for g(- 1)
g(- 1) = (- 1)² - 2 = 1 - 2 = - 1
Then
f(8) + g(- 1) = - 7 + (- 1) = - 7 - 1 = - 8