Answer:
400
Step-by-step explanation:
The computation of the sample size needed is shown below:
Since at the sample size of 200 there is a standard deviation of 0.08
But when the standard deviation is 0.04 so the sample size is 400
As sample standard deviation would be inversely proportional to the square root of the sample size
Answer:
34
Step-by-step explanation:
$1.25 = 125 cents.
$42 = 4200 cents
Tickets sold at 75 cents = x
Tickets sold at 125 cents = y
x + y = 40
75x + 125y = 4200
Multiply the first equation by 75
75x + 75y = 3000
75x + 125y = 4200
Subtract the the second equation from the first.
75x + 75y = 3000
- 75x + 125y = 4200
-------------------------------
0 - 150y = - 1200
Divide both sides by - 150
-150y/-150 = -1200/-150
y = 8
Substitute y = 8 into the first equation
x + y = 42
x + 8 = 42
x = 42 - 8
x = 34
34 tickets were sold for 75 cents
8 tickets were sold for $1.25
Answer:
3. 9x
4. D. -5v + 4
Step-by-step explanation:
3. (-3+12)v
= 9v
4. Combine like terms:
(-2v - 3v) + (8 - 4)
= -5v + 4
When Anne Betty and Cynthia compared the amount of money each had, they discovered that Anne and Betty together had $12 Betty and Cynthia together had $18 and Anne and Cynthia together had $10.
<span>Who had the least amount of money? and how much was it?
a +b = 12
b + c = 18
a + c = 10
So what I did is simple XD A logical guess and check. I started with a = 1, but that was to little. And also didn't match up. So I kept going up and got a = 2, b = 10, and c = 8</span>
Answer: the cost of one package of macadamia nut chip cookie dough is $1.5
the cost of one package of triple chocolate cookie dough is $2.5
Step-by-step explanation:
Let x represent the cost of one package of macadamia nut chip cookie dough.
Let y represent the cost of one package of triple chocolate cookie dough.
Mrs. Julien’s class sold 25 packages of macadamia nut chip cookie dough and 30 packages of triple chocolate cookie dough for a total of $112.50. This means that
25x + 30y = 112.5 - - - - - - - - - - - - -1
Mrs. Castillejo’s class sold 8 packages of macadamia nut chip cookie dough and 45 packages of triple chocolate cookie dough for a total of $124.50. This means that
8x + 45y = 124.5 - - - - - - - - - - -2
Multiplying equation 1 by 8 and equation 2 by 25, it becomes
200x + 240y = 900
200x + 1125 = 3112.5
Subtracting, it becomes
- 885y = - 2212.5
y = - 2212.5/- 885
y = 2.5
Substituting y = 2.5 into equation 1, it becomes
25x + 30 × 2.5 = 112.5
25x + 75 = 112.5
25x = 112.5 - 75 = 37.5
x = 37.5/25 = 1.5
The method used is the elimination method. It is more convenient to use.
