11.5 is a rational number
Answer:
Mean and Variance of the number of defective bulbs are 0.5 and 0.475 respectively.
Step-by-step explanation:
Consider the provided information,
Let X is the number of defective bulbs.
Ten light bulbs are randomly selected.
The likelihood that a light bulb is defective is 5%.
Therefore sample size is = n = 10
Probability of a defective bulb = p = 0.05.
Therefore, q = 1 - p = 1 - 0.05 = 0.95
Mean of binomial random variable: 
Therefore, 
Variance of binomial random variable: 
Therefore, 
Mean and Variance of the number of defective bulbs are 0.5 and 0.475 respectively.
Ok so...
You want to move the decimal point to the right until the number is greater than 1 but less than 10.
The number will end up being 5.2
You moved the decimal point 3 times to the right.
So it will be 5.2 x 10^-3. It is negative because you moved it to the right. The exponent would be positive if you moved it to the left
5 : 3
D1 = 3km = 3000 m (1km = 1000m)
D2 = 1800m
Ratio of D1:D2
=3000/1800
=1000/600 (dividing by 3)
=10/6 (dividing by 100)
=5/3 (dividing by 2)
= 5 : 3