we know that in direct variation as x increase y also increases.
in indirect variation x decreases y increase and vice versa.
in part a we have x at top (numerator ) and y at denominator it mean indirect variation (as x increases y decreases).
to find k we know that for indirect variation xy=k
if we rewrite the equation x=9/y we get xy=9
which mean k=9 .
in part b we have 4xy=20 if we simplify this equation we get
so here if we rewrite in terms of x.
we get x=5/y which represents indirect variation.
and we know xy=k
we have xy=5 .so k=5
Answer:
P(x) = 45/100 = 0.45
Mean sample distribution = probability x number sampled by the survey.
Mean sample distribution = 0.45 x 800 = 360.00 to two decimal places.
Step-by-step explanation:
Convert the percentage to decimal probability.
45%. P(x) = 45/100 = 0.45
If there are ranges of probability values, we construct a probability distribution table. This is not necessary in the case of one probability value(45%)
Multiply the probability by the number adults to be surveyed on whether they have received phishing emails.
0.45 x 800 = 360.
Here, we assume that the 45% recorded by 2005 data, is still valid for the recent trends.
Answer:
And we can find this probability with this difference:
Step-by-step explanation:
Previous concepts
Normal distribution, is a "probability distribution that is symmetric about the mean, showing that data near the mean are more frequent in occurrence than data far from the mean".
The Z-score is "a numerical measurement used in statistics of a value's relationship to the mean (average) of a group of values, measured in terms of standard deviations from the mean".
Solution to the problem
Let X the random variable that represent the amount of cofee shops of a population, and for this case we know the distribution for X is given by:
Where 
and 
We are interested on this probability
And the best way to solve this problem is using the normal standard distribution and the z score given by:
If we apply this formula to our probability we got this:
And we can find this probability with this difference:
Answer:
a = 3, b = 0, c = 0, d = -2
Step-by-step explanation:
<em>To find the reflection Multiply the matrices</em>
∵ The dimension of the first matrix is 2 × 2
∵ The dimension of the second matrix is 2 × 3
<em>1. Multiply the first row of the 1st matrix by each column in the second matrix add the products of each column to get the first row in the 3rd matrix.</em>
2. Multiply the second row of the 1st matrix by each column in the second matrix add the products of each column to get the second row of the 3rd matrix
![\left[\begin{array}{ccc}1&0\\0&-1\end{array}\right]](https://tex.z-dn.net/?f=%5Cleft%5B%5Cbegin%7Barray%7D%7Bccc%7D1%260%5C%5C0%26-1%5Cend%7Barray%7D%5Cright%5D)
× ![\left[\begin{array}{ccc}0&3&0\\0&0&2\end{array}\right]](https://tex.z-dn.net/?f=%5Cleft%5B%5Cbegin%7Barray%7D%7Bccc%7D0%263%260%5C%5C0%260%262%5Cend%7Barray%7D%5Cright%5D)
= ![\left[\begin{array}{ccc}(1*0+0*0)&(1*3+0*0)&(1*0+0*2)\\(0*0+-1*0)&(0*3+-1*0)&(0*0+-1*2)\end{array}\right]=\left[\begin{array}{ccc}0&3&0\\0&0&-2\end{array}\right]](https://tex.z-dn.net/?f=%5Cleft%5B%5Cbegin%7Barray%7D%7Bccc%7D%281%2A0%2B0%2A0%29%26%281%2A3%2B0%2A0%29%26%281%2A0%2B0%2A2%29%5C%5C%280%2A0%2B-1%2A0%29%26%280%2A3%2B-1%2A0%29%26%280%2A0%2B-1%2A2%29%5Cend%7Barray%7D%5Cright%5D%3D%5Cleft%5B%5Cbegin%7Barray%7D%7Bccc%7D0%263%260%5C%5C0%260%26-2%5Cend%7Barray%7D%5Cright%5D)
Compare the elements in the answer with the third matrix to find the values of a, b, c, and d
∴ a = 3
∴ b = 0
∴ c = 0
∴ d = -2
