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
The answers are A and D.
The numbers that you cannot simplify without having a radical in the answer are irrational numbers.
√(4/16) = 1/4 or -1/4, rational number
√(9/16) = 3/4 or -3/4, rational number
√(9/4) = 3/2 or -3/2, rational number
√(3/16) = √(3)/4, NOT a rational number, cannot remove radical
√(3/4) = √(3)/2, NOT a rational number, cannot remove radical
Answer:
Step-by-step explanation:
Let
D(t) = the distance to the safe zone (measured in meters)
t = time (measured in seconds)
<u>Given:</u>
Rachel's rate = 24 meters per second
At 
seconds 
meters
<u>Find:</u> D(t)
Rachel's rate is the slope of the function D(t). Since the distance is decreasing when the time is increasing, the slope must be negative.
Hence, the function expression is
To find b, substitute and 
So,
Find the Least Common Denominator (LCD) which is 28.
-1/4 (7) = -7/28
-3/7 (4) = -12/28
-7 - 12 = -19
-19/28
Simplify if you can.
