Answer:
-5≤x <1
Step-by-step explanation:
sqrt( x+5) / sqrt(1-x)
The numerator must be greater than zero since it is a square root
sqrt(x+5) ≥0
Square each side
x+5≥0
x≥-5
The denominator must be greater than zero (the denominator cannot be zero)
sqrt(1-x)> 0
Square each side
1-x > 0
1>x
Putting these together
-5≤x <1
Variance is the standard deviation squared but we're not going to use that now. Let's first calculate the mean:
mean = (17+13+13+22+11+20)/6 = 16.
Now for each value, let's see how far it is from this mean. We'll square these distances and average them. That's our variance.
17 distance 1 squared = 1
13 distance 3 squared = 9
13 distance 3 squared = 9
22 distance 6 squared = 36
11 distance 5 squared = 25
20 distance 4 squared = 16
Now average these outcomes:
variance = (1+9+9+36+25+16)/6 = 16.
So the variance by coincidence is the same as the mean.
Answer C is your answer.
Answer:
The answer is 144
Step-by-step explanation:
Let Sam be (S+8) years while his sister is S years.
S(S+8) = 105
S^2+8S-105 = 0
(S+15)(S-7) = 0
Sam’s sister is 7 years and Sam is 15 years old.
