Answer:
Mean age: 48
Standard deviation: 4
Step-by-step explanation:
a) Mean
The formula for Mean = Sum of terms/ Number of terms
Number of terms
= 42 + 54 + 50 + 54 + 50 + 42 + 46 + 46 + 48+ 48/ 10
= 480/10
= 48
The mean age is 48
b) Standard deviation
The formula for Standard deviation =
√(x - Mean)²/n
Where n = number of terms
Standard deviation =
√[(42 - 48)² + (54 - 48)² + (50 - 48)² +(54 - 48)² + (50 - 48)² +(42 - 48)² + (46 - 48)² + (46 - 48)² + (48 - 48)² + (48 - 48)² / 10]
= √-6² + 6² + 2² + 6² + 2² + -6² + -2² + -2² + 0² + 0²/10
=√36 + 36 + 4 + 36 + 4 + 36 + 4 + 4 + 0 + 0/ 10
=√160/10
= √16
= 4
The standard deviation of the ages is 4
Answer: A
Step-by-step explanation:
The easiest way to solve this problem would to first figure out how long it takes for Mak to run 1 mile. To do that, you would need to divide 50 by 4 which would give you 12.5. So, it takes Mak 12 and a half minutes to run 1 mile. From there, you would need to multiply 12.5 by 10 to get 125. Finally, you wold need to simplify 125 minutes to hours giving you 2 hours and 5 minutes.
1.85x-42.55>100 is the inequality. 42.55 is the amount already raised, 1.85x is number of laps times the money raised by them.
Answer: 250
Step-by-step explanation: