Answer:
327 children and 318 adults
Step-by-step explanation:
The x be the amount of children and y be the amount of adults that were at the swimming pool. We can use this to set up a system of equations:
x+y=645
1.75x+2.50y=1367.25
Move y to the other side in the first equation to isolate x and solve the system using substitution:
x=645-y
1.75(645-y)+2.50y=1367.25
Distribute
1128.75-1.75y+2.50y=1367.25
1128.75+0.75y=1367.25
Subtract 1128.75 from both sides
0.75y=238.5
Divide both sides by 0.75
y=318
x=645-y
x=645-318
x=327
327 children and 318 adults swam at the pool that day
Answer:
A. 
Step-by-step explanation:
We want to find the Z-score of 
if the population mean is 
,and the population standard deviation is 
.
We use the formula:
We substitute the values to obtain:
The correct answer is A.
If I’m not mistaken, the answer is C.
Step-by-step explanation:
(2, -3) is in the 4th quadrant. By the counter clockwise rotation of 90° around the origin, it will be in the 1st quadrant.
Any point in the 1st quadrant has both positive x and y coordinates.
So the answer is (3, 2).
Answer:
The probability is 1/17.
Step-by-step explanation:
The total number of ways in which 2 cards can be selected from a pack of 52 cards is 
The total number of combinations of 2 cards with hearts equals 
Thus the probability of the event that both the cards have hearts becomes
