Study the exercises in which both addends are negative. What do you notice about the sum?
1 answer:
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Answer:
- adult: $11
- children: $7
Step-by-step explanation:
The sales on the two days can be expressed using equations that can be solved for ticket prices.
<h3>Setup</h3>Let x and y represent the prices of adult and children's tickets, respectively. Then the sales revenue for the two days can be expressed in the equations ...
- 5x +7y = 104
- 7x +3y = 98
One of the easiest solution methods is to use a graphing calculator. The first attachment shows the prices are $11 for an adult ticket; $7 for children tickets.
Using the matrix functions of a calculator, the augmented matrix of the equation coefficients can be reduced to row-echelon form. This, too, shows the solution to be (adult price, children price) = ($11, $7). See the second attachment. (The solution is the right-most column of the reduced matrix.)
Yet another solution method can use the coefficients from the equations written in general form:
- 5x +7y -104 = 0
- 7x +3y -98 = 0
In this form, we define three products of "cross multiplication":
Δ1 = (5)(3) -(7)(7) = -34
Δ2 = (7)(-98) -(3)(-104) = -374
Δ3 = (-104)(7) -(-98)(5) = -238
Using those, we find the variable values to be ...
x = Δ2/Δ1 = -374/-34 = 11
y = Δ3/Δ1 = -238/-34 = 7
(adult price, children price) = ($11, $7)
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You can read more about the cross-multiplication method here:
Answer:
1) (1,3,4.7)
2) 6.8
3) the square root of the variance
4) has the same units as the underlying data
5) It has predictive power.
Step-by-step explanation:
From question one, it is possible to use an excel formula to calculate the variance of the set of numbers.
Now, to calculate the variance in an Excel sheet:
Make sure your data is in a single range of cells in Excel.
If your data represents the entire population, enter the formula as "=VAR. P(A1:A4). Since, we were given four variables
The variance for your data will be displayed in the cell.
i.e for set of numbers (7, 8, 9, 10)
variance = (VAR. P(A1:A4))
= 1.25
for set of numbers (1, 3, 4, 7)
variance = (VAR. P(A1:A4))
= 4.69
for set of numbers (4,2,1, 0)
variance = (VAR. P(A1:A4))
= 2.19
for set of numbers (1, 0, 2, 4)
variance = (VAR. P(A1:A4))
= 2.19
The set of numbers (1,3,4.7) indicates the largest variance from the foregoing.
2) What is the population variance of the following set of numbers: 3, 5, 8, 9, 10?
Using the same method explained in question 1, the population variance of the following set of numbers 3,5,8,9,10 can be calculated as:
For the set of numbers (3, 5, 8, 9, 10)
Variance = (VAR. P(A1:A5)) since it contains five sets.
= 6.8
3) Variance can be defined as the average of the squared differences from the Mean. Therefore, Standard deviation is the square root of the variance which is given as:
where;
s = sample standard deviation
N = the number of observations
= the observed values of a sample item.
x= the mean value of the observations
4) Standard deviation is useful because it has the same units as the underlying data
5) Of all the characteristics of Standard deviation when relating to finance, Standard deviation do not possess predictive power.