Answer:
And we can find this probability using the normal standard distribution table and we got:
And the percentage faster than 13.28 seconds would be 91.9%
Step-by-step explanation:
Let X the random variable that represent the runtimes of a population, and for this case we know the distribution for X is given by:
Where
and
We want to find this probability:
And we can use the z score formula given by:
Using this formula we have:
And we can find this probability using the normal standard distribution table and we got:
And the percentage faster than 13.28 seconds would be 91.9%
The two numbers are 5 and 12.
Using the normal distribution, it is found that the probability is 0.16.
<h3>Normal Probability Distribution</h3>
In a normal distribution with mean
and standard deviation
, the z-score of a measure X is given by:

- It 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, which is the percentile of X.
In this problem, the mean and the standard deviation are given by, respectively,
.
The proportion of students between 45 and 67 inches is the p-value of Z when <u>X = 67 subtracted by the p-value of Z when X = 45</u>, hence:
X = 67:


Z = -1
Z = -1 has a p-value of 0.16.
X = 45:


Z = -8.3
Z = -8.3 has a p-value of 0.
0.16 - 0 = 0.16
The probability is 0.16.
More can be learned about the normal distribution at brainly.com/question/24663213
Answer:
(x + 7)(x + 3).
Step-by-step explanation:
x^2 +10x + 21
21 = 7 * 3 and 10 = 7 +3
so the factors are
(x + 7)(x + 3).
Y=-5x+9
3x+2(-5x+9)=4
3x-10x+18=4
-7x=4-18
-7x=-14
x=2
5(2)+y=9
10+y=9
y=9-10
y=-1
The answer is (2,-1) :)