Making the assumption that your problem looks like this,

we use the distributive property to multiply:
Answer:
The margin of error for a 90% confidence interval is 16.4
Step-by-step explanation:
We are given the following in the question:
Sample size, n = 25
Standard deviation = 50

Margin of error =

Putting the values, we get,

Thus, the margin of error for a 90% confidence interval is 16.4
1. W=16-4=12
2. X=-12-7=-19
3. W=6+15=21
5. y=-2+9=7
6. q=35/7=5
Both questions 4 and 7 aren’t written correctly!!
Answer:
The proportion of infants with birth weights between 125 oz and 140 oz is 0.1359 = 13.59%.
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.
In this question, we have that:

The proportion of infants with birth weights between 125 oz and 140 oz is
This is the pvalue of Z when X = 140 subtracted by the pvalue of Z when X = 125. So
X = 140



has a pvalue of 0.9772
X = 125



has a pvalue of 0.8413
0.9772 - 0.8413 = 0.1359
The proportion of infants with birth weights between 125 oz and 140 oz is 0.1359 = 13.59%.
She buys 2 boxes each week for a year (there is 52 weeks in a year) = 2 x 52 = 104 boxes per year
if each box contains 8 granola bars...and she buys 104 boxes, then she buys:
104 * 8 = 832 granola bars