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:
![Z = \frac{X - \mu}{\sigma}](https://tex.z-dn.net/?f=Z%20%3D%20%5Cfrac%7BX%20-%20%5Cmu%7D%7B%5Csigma%7D)
- 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 = \frac{X - \mu}{\sigma}](https://tex.z-dn.net/?f=Z%20%3D%20%5Cfrac%7BX%20-%20%5Cmu%7D%7B%5Csigma%7D)
![Z = \frac{420 - 400}{30}](https://tex.z-dn.net/?f=Z%20%3D%20%5Cfrac%7B420%20-%20400%7D%7B30%7D)
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:
(a) 0.5899
(b) 0.9166
Step-by-step explanation:
Let X be the random variable that represents the height of a woman. Then, X is normally distributed with
= 62.5 in
= 2.2 in
the normal probability density function is given by
, then
(a)
= 0.5899
(in the R statistical programming language) pnorm(63, mean = 62.5, sd = 2.2)
(b) We are seeking
where n = 37.
is normally distributed with mean 62.5 in and standard deviation
. So, the probability density function is given by
, and
= 0.9166
(in the R statistical programming language) pnorm(63, mean = 62.5, sd = 2.2/sqrt(37))
You can use a table from a book to find the probabilities or a programming language like the R statistical programming language.
Mean 6.6
Median 6
Mode 3
Range 10
not positive on the 6.6 but the rest should be good
Answer:
Fixed cost $14 -350 messages
variable $ 0.25 each message<u> i think</u>
Step-by-step explanation:
Answer:
2/10 or 1/5
Step-by-step explanation:
there are 10 equal 'slices'
then count those with a J
that would be 2