Answer:
-19/10,-18/10,-17/10
Step-by-step explanation:
multiply the both numbers up and down by 10.
then find the numbers
Using the normal distribution, it is found that 25.14% of the batteries will last more than 420 hours.
<h3>Normal Probability Distribution</h3>
The z-score of a measure X of a normally distributed variable with mean
and standard deviation
is given by:

- The z-score measures how many standard deviations the measure is above or below the mean.
- Looking at the z-score table, the p-value associated with this z-score is found, which is the percentile of X.
In this problem, we have that the mean and the standard deviation are given, respectively, by:
.
The proportion of the batteries will last more than 420 hours is <u>one subtracted by the p-value of Z when X = 420</u>, hence:


Z = 0.67
Z = 0.67 has a p-value of 0.7486.
1 - 0.7486 = 0.2514.
0.2514 = 25.14% of the batteries will last more than 420 hours.
More can be learned about the normal distribution at brainly.com/question/24663213
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The 4th one, since both values have less than .5 after the decimal
The answer will be 9 1/12 because if you add them up you get 11/12. So the mixed number would be 9 1/12
There are 2.54 cm in 1 inch. Since we are estimating, we can round the average growth per year to .5 cm which would give you roughly 5 years per inch of diameter (2.5 / .5 = 5). Since we have a tree with a 4 inch diameter, we can estimate the age of the tree is...
4 inches x 5 years/inch = 20 years old.