To solve this, we use the z test.
The formula:
z = (x – u) / s
where x is sample value = 20, u is the mean = 15, and s is
the standard deviation = 2.5
z = (20 – 15) / 2.5
z = 2
Since we are looking for values greater than 20, this is
right tailed test. We use the standard distribution tables to find for P.
P = 0.0228
Therefore:
number of students = 100 * 0.0228 = 2.28
<span>2 to 3 students will get greater than 20 measurement</span>
First distribute the negative through the parenthesis on the left and the 2 on the right.
-5 -15y +1 = 14y -32 - y
Combine like terms on the right and left
-4 -15y = 13y -32
Now move the variables to one side and the constants to the other.
Subtract 13y from both sides
-4 -28y = -32
Add 4 to both sides
-28y = -28
Divide both sides by -28
y = 1
Answer:
Step-by-step explanation:
Each ticket is $15. The number of tickets is what we are trying to solve for. The class spends a certain amount of money to prepare for the formal. They hope that the money they make in ticket sales is MORE than what they spend. The expression that represents the number of tickets at $15 each is 15x, where x is the number of tickets. They hope that the sales are greater than what they spend, so what we have so far is
15x >
Greater than what, though? What do they spend? They spend 600 for the food, so
15x > 600...
but they also have to print a certain, unknown number of tickets at .50 each. The expression that represents the printing of each ticket is .5x (we can drop the 0; it doesn't change the answer or make it wrong if we drop it off). So the cost for this affair is the food + the printing.
15x > 600 + .5x
Solve this inequality for x. Begin by subtracting .5 from both sides to get
14.5x > 600 so
x > 41.3
Because we are not selling (or printing) .3 of a ticket, it's safe to say (and also correct!) that they need to sell (and print) 41 tickets. If they sell 41 tickets, the profit is found by
15(41) > 600 + .5(41)
615 > 600
This means that at 41 tickets, they make a profit. At 40 tickets, the inequality looks like this:
15(40) > 600 + .5(40) and
600 > 620. This is not true, so 40 tickets isn't enough.
PEMDAS tells us to use multiplication and division before addition and subtraction.
<u>-5(8) </u>÷ 10 - <u>14 ÷ 7</u> - <u>(-2)(3)</u>
<u> -40 ÷ 10</u> - 2 - -6
<u>-4 - 2 </u> + 6 <em>two negatives make a positive so - - 6 = + 6</em>
<u> -6 +6</u>
0
Answer: 0
