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:
18
Step-by-step explanation:
2:3 x 9
18:27
18 + 27 = 45
Answer:
11/4 seconds
Step-by-step explanation:
We can see from the given equation that the height at the diving board is h = 3.
This is because the h(t) equation has that +3 at the end, which denotes the initial height of the diver, the height when he is standing on the board before jumping.
To find where h(t) = 3 is true, we need to set h(t) equal to 3 and solve for t.
h(t) = 3
h(t) = -4t^2 + 11t + 3 = 3
-4t^2 + 11t + 3 - 3 = 0
-4t^2 + 11t = 0
t*(-4t + 11) = 0
so h(t) = 3 when t = 0 and when t = 11/4 sec
we already know that at t = 0 the height is 3, it is the initial height given from the equation, so we want to use the other solution for t.
the diver is back at the height of the diving board at t = 11/4 sec
Answer:
6x + 2y =5
y + 3x= 2
Step-by-step explanation: