Answer:
mean = 1 power failure
variance = 1 (power failure)²
Step-by-step explanation:
Since the mean is computed as
mean = E(x) = ∑ x * p(x) for all x
then for the random variable x=power failures , we have
mean = ∑ x * p(x) = 0 * 0.4 + 1* 0.3 + 2*0.2 + 3* 0.1 = 1 power failure
since the variance can be calculated through
variance = ∑[x-E(x)]² * p(x) for all x
but easily in this way
variance = E(x²) - [E(x)]² , then
E(x²) = ∑ x² * p(x) = 0² * 0.4 + 1²* 0.3 + 2²*0.2 + 3²* 0.1 = 2 power failure²
then
variance = 2 power failure² - (1 power failure)² = 1 power failure²
therefore
mean = 1 power failure
variance = 1 power failure²
Tan(A) = opposite / adjacent
if we call opposite "a" and adjacent "b"
tan(A) = a/b
then...
tan(B) = b/a
because it's on the other angle so "b" is now opposite angle B and "a" is adjacent.
So really you just need to take the reciprocal of the given values.
6. tan(A) = 1.25
reciprocal is flipping the value and using it to divide by 1.
you can keep as decimal , 1/1.25 = 0.8
or change to fraction
1.25 = 5/4
tan(B) = 4/5 or 0.8
7. tan(B) = 0.5
1/0.5 = 2
tan(A) = 2
8. tan(B) = 1
tan(A) = 1
Answer:
the length will need to be increased by 5 feet
Answer: 540
Step-by-step explanation:
Given : The owner of a stereo store wants to advertise that he has many different sound systems in stock.
Number of different CD players =6
Number of different receivers= 10
Number of different speakers = 9
We are assuming that a sound system consists of one of each .
Then by Fundamental principle of counting , we have
The number of different sound systems can he advertise = (Number of different CD players)x (Number of different receivers) x(Number of different speakers)
= 6 x10 x 9 =540
Hence, the number of different sound systems can he advertise =540
