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%.
see attached picture for solutions:
Answer:
x = 56
Step-by-step explanation:
To start, distribute the 1/3 onto the x and the 4 in the parenthesis. That leaves you with
1/3x + 4/3 = 20
We want the x value by itself so we're going to subtract the 4/3 from the left and the right side, leaving us with
1/3x + 4/3 = 20 - 4/3
1/3x = 18 & 2/3 (since we're dealing with fractions, I'm going to change the 18 & 2/3 into an improper fraction just to make the next step easier.)
1/3x = 56/3
The last step is to divide the 1/3 off of the x, so x is by itself. To divide a fraction by a fraction, just flip the fraction you're dividing with and multiply.
56/3 x 3/1 = 56 (56 x 3 is 168, and 3 x 1 is 3, so when you reduce 168/3, you get 56)
So, 56 is our answer, because after dividing off the 1/3, we're left with x = 56
<u>Answer:</u> 5 years!
<u>Reasoning:</u>
Year 1: 2700 x .70=1890
Year 2: 1890 x .70= 1323
Year 3: 1323 x .70= 926.1
Year 4: 926.1 x .70= 648.27
Year 5: 648.27 x .70=453.79
3.36242487588 is the answer
