The probability is 0.1429.
The probability that the first person chosen is a boy is 5/7. The probability that the second is a boy is 4/6; the third, 3/5; and the fourth, 2/4. Both the numerator and denominator decrease every time, because you lose a boy to choose from and you lose a student to choose from as well. This gives us:
5/7(4/6)(3/5)(2/4) = 120/840 = 0.1429.
Answer:
9+x
Step-by-step explanation:
The area of a rectangle is the width multiplied by the length. Working backwards, then, you can find the width or the length by dividing the area by the other one. In this case, the length of the rectangle is the area, or 81-x^2, divided by the width, 9-x. 81-x^2 factored out is (9-x)(9+x), so dividing this by 9-x yields a length of 9+x. Hope this helps!
Using the normal distribution, it is found that the correct option is:
In a <em>normal distribution</em> 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.
In this problem:
- The mean on the Wechsler Scale is of 100, hence
.
- The standard deviation is of 17, hence
.
- Brianna had an score of 117, hence

Then:



Hence, the option d is correct.
To learn more about the normal distribution, you can check brainly.com/question/24663213
5 miles per hour ;)
Just multiply by 2 to get 5 miles in 1 hour