Answer:
a) Matrix B = ![\left[\begin{array}{c}5\\7\\9\end{array}\right]](https://tex.z-dn.net/?f=%5Cleft%5B%5Cbegin%7Barray%7D%7Bc%7D5%5C%5C7%5C%5C9%5Cend%7Barray%7D%5Cright%5D)
b) Matrix AB = ![\left[\begin{array}{c}2525\\3620\\2845\\3705\end{array}\right]](https://tex.z-dn.net/?f=%5Cleft%5B%5Cbegin%7Barray%7D%7Bc%7D2525%5C%5C3620%5C%5C2845%5C%5C3705%5Cend%7Barray%7D%5Cright%5D)
c) $12,695
Step-by-step explanation:
Matrix A = ![\left[\begin{array}{ccc}225&110&70\\95&160&225\\280&65&110\\0&240&225\end{array}\right]](https://tex.z-dn.net/?f=%5Cleft%5B%5Cbegin%7Barray%7D%7Bccc%7D225%26110%2670%5C%5C95%26160%26225%5C%5C280%2665%26110%5C%5C0%26240%26225%5Cend%7Barray%7D%5Cright%5D)
a) Matrix B = ![\left[\begin{array}{c}5\\7\\9\end{array}\right]](https://tex.z-dn.net/?f=%5Cleft%5B%5Cbegin%7Barray%7D%7Bc%7D5%5C%5C7%5C%5C9%5Cend%7Barray%7D%5Cright%5D)
Gross Receipt = AB
.
= ![\left[\begin{array}{c}2525\\3620\\2845\\3705\end{array}\right]](https://tex.z-dn.net/?f=%5Cleft%5B%5Cbegin%7Barray%7D%7Bc%7D2525%5C%5C3620%5C%5C2845%5C%5C3705%5Cend%7Barray%7D%5Cright%5D)
c) Total revenue is the sum of receipts from 4 cinemas given in part b
Hence,
Total revenue = $2525 + $3620 + $2845 + $3705 = $12,695
total number of student in the data set in the dataset is 90
Answer:



The standard deviation will remain unchanged.
Step-by-step explanation:
Given

Solving (a): The range
This is calculated as:

Where:

So:


Solving (b): The variance
First, we calculate the mean




The variance is calculated as:

So, we have:
![\sigma^2 =\frac{1}{6-1}*[(136 - 135)^2 +(129 - 135)^2 +(141 - 135)^2 +(139 - 135)^2 +(138 - 135)^2 +(127 - 135)^2]](https://tex.z-dn.net/?f=%5Csigma%5E2%20%3D%5Cfrac%7B1%7D%7B6-1%7D%2A%5B%28136%20-%20135%29%5E2%20%2B%28129%20-%20135%29%5E2%20%2B%28141%20-%20135%29%5E2%20%2B%28139%20-%20135%29%5E2%20%2B%28138%20-%20135%29%5E2%20%2B%28127%20-%20135%29%5E2%5D)
![\sigma^2 =\frac{1}{5}*[162]](https://tex.z-dn.net/?f=%5Csigma%5E2%20%3D%5Cfrac%7B1%7D%7B5%7D%2A%5B162%5D)

Solving (c): The standard deviation
This is calculated as:


--- approximately
Solving (d): With the stated condition, the standard deviation will remain unchanged.
a. The first part asks for how many ways they can be seated together in a row. Therefore we want the permutations of the set of 6 people, or 6 factorial,
6! = 6
5
= 30
4
= 360
2 = 720 possible ways to order 6 people in a row
b. There are two cases to consider here. If the doctor were to sit in the left - most seat, or the right - most seat. In either case there would be 5 people remaining, and hence 5! possible ways to arrange themselves.
5! = 5
4
= 20
3
= 120
1 = 120 possible ways to arrange themselves if the doctor were to sit in either the left - most or right - most seat.
In either case there are 120 ways, so 120 + 120 = Total of 240 arrangements among the 6 people if the doctor sits in the aisle seat ( leftmost or rightmost seat )
c. With each husband on the left, there are 3 people left, all women, that we have to consider here.
3! = 3
2 6 ways to arrange 3 couples in a row, the husband always to the left
Answer: D.
Step-by-step explanation:
The associative property of addition states that numbers can be added together regardless of how they are grouped.
Answer A shows a property of multiplication.
Answer B shows the additive identity property.
Answer C shows the commutative property.
However, answer D shows that the numbers can be added regardless of how they are grouped.