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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Answer:
the answer is 230 calories :)
Step-by-step explanation:
divide 160 by 16 to find out how much 1-oz is then times it by 23 to get the amount of calories in 23-oz. There you go I hope it helps :)
10 ball bearings is the correct answer, i hope it works
Answer:
A sample size of 345 is needed so that the confidence interval will have a margin of error of 0.07
Step-by-step explanation:
In a sample with a number n of people surveyed with a probability of a success of
, and a confidence level of
, we have the following confidence interval of proportions.

In which
z is the zscore that has a pvalue of
.
The margin of error of the interval is given by:

In this problem, we have that:

99.5% confidence level
So
, z is the value of Z that has a pvalue of
, so
.
Using this estimate, what sample size is needed so that the confidence interval will have a margin of error of 0.07?
This is n when M = 0.07. So







A sample size of 345 is needed so that the confidence interval will have a margin of error of 0.07
Answer:
X= -50
Step-by-step explanation:
Remove the parenthesis
multiply both sides by two
x - 6 = -56
Move the 6 to the other side
x = -56 + 6
x = -50