Answer:
The correct option is;
e. 2500
Step-by-step explanation:
The formula for sample size is given by the following formula;
At 95%, z = 1.96
ε = Margin of error = 0.02 = 2%
Finding the sample size, n, given only the margin of error is by the following formula;
Margin of error = 100/√n
Therefore, we have;
2 = 100/√n
√n = 100/2 = 50
n = 50² = 2500
Therefore, the correct option is e. 2500.
9514 1404 393
Answer:
- 7 adult tickets
- 9 child tickets
Step-by-step explanation:
Using the variables defined in the problem statement, we can write the equations ...
a + c = 16 . . . . . . . . . . . . number of tickets bought
10.50a +7.50c = 141 . . . cost of tickets bought
Substituting for c in the second equation, we get ...
10.50a +7.50(16 -a) = 141
3.00a +120 = 141 . . . . . . . . simplify
3a = 21 . . . . . . . . . . . subtract 120
a = 7 . . . . . . . . divide by 3
16 -a = c = 9 . . . . . . . find the number of child tickets
They bought 7 adult tickets and 9 child tickets.
_____
If you examine the solution, you see that the number of adult tickets (the higher priced item) is the quotient of the difference between the actual expenditure (141) and the amount that would have been spent on all child tickets (16×7.50=120), and the difference in ticket prices (10.50-7.50=3.00). Knowing this, you can often work problems of this kind in your head.
When you are trying to figure this out put them into a list vertically. Remember, ONE X CAN'T HAVE TO Y's BUT ONE Y CAN HAVE MULTIPLE X's, But dont worry about the y's right now. Lets focus on the x's.
Ask yourself, Are there 2 or more x's that are the same value?
Yes) Continue to next step
No) It's a function :)
If there are 2 or more of the same x value, ask your self now if those x's have different y Values.
Yes) It is not a function, one x can not have more that 1 y value
No) Its a function :)
Remove both sets of brackets.
18 - 9x - 8 + 12x > 9 Collect like terms on the left.
12x - 9x + 18 - 8 > 9
3x + 10 > 9 Subtract 10 from both sides.
3x > 9 - 10
3x > - 1 divide by 3
x > -1/3
Notice what the graph is telling you. A blue dotted line is going through x = - 1/3 or - 0.3333
Everything to the right of - 0.333 is colored blue and that means anything to the right if going to be a solution to the inequality. To confirm this for yourself, try zero and 1. Both should give larger than 9 solutions.