Answer:
y=-2
Step-by-step explanation:
The formula for inverse variation is
xy =k
if y=7 when x=-2, we can substitute these numbers in to find k
(-2)(7) =k
-14 =k
The equation becomes
xy = -14
Let x =7
7y = -14
Divide each side by 7
7y/7 = -14/7
y = -2
Solution:
As, in a pack of cards, there are 26 black cards and 26 red cards.
Probability of an event = 
Probability of drawing a black card from a pack of 52 cards = 
As each card drawn is replaced,Each black card draw is an independent with another black card draw.
Probabilities of drawing a black card on each of four trial=
![\frac{1}{2}\times \frac{1}{2}\times \frac{1}{2}\times \frac{1}{2}=[\frac{1}{2}]^4](https://tex.z-dn.net/?f=%5Cfrac%7B1%7D%7B2%7D%5Ctimes%20%5Cfrac%7B1%7D%7B2%7D%5Ctimes%20%5Cfrac%7B1%7D%7B2%7D%5Ctimes%20%5Cfrac%7B1%7D%7B2%7D%3D%5B%5Cfrac%7B1%7D%7B2%7D%5D%5E4)
Answer:
m = 5
a = -3
b = -15
Step-by-step explanation:
(m - 2) = 3 for x^2
(2a + 3) = - (m - 2) = (2 - m) for x^1
(b + 6) = (2a - 3) for x^0
Using the normal distribution, we have that:
a) The sketch of the situation is given at the end of this answer.
b) The probability is:

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:
- Mean of 4.1 years, thus
. - Standard deviation of 1.3 years, thus
.
Item a:
The part between 2.8 and 7 years is shaded on the sketch given at the end of this answer.
Item b:
The probability is the <u>p-value of Z when X = 7 subtracted by the p-value of Z when X = 2.8</u>, thus:
X = 7:



has a p-value of 0.9871.
X = 2.8:



has a p-value of 0.1587.
0.9871 - 0.1587 = 0.8284, thus:

A similar problem is given at brainly.com/question/25151638
Let’s call the sum of the set of five numbers S and the sixth number N. We know the mean of the set of five numbers is 3k, so we can write the equation S/5 = 3k or S = 15k. When we add the sixth number the mean increases by k, so we can write the equations (S + N)/6 = 4k or S + N = 24k. Using S = 15k, we find that N = 9k. The ratio of the sixth number to the sum of the set of five numbers is therefore N/S = 9k/15k = 3/5.