Answer:
The expected value of X is 2 with a standard deviation of 1.34.
Step-by-step explanation:
For each speaker, there are only two possible outcomes. Either it is defective, or it is not. The probability of a speaker being defective is independent of other speakers. So we use the binomial probability distribution to solve this question.
Binomial probability distribution
Probability of exactly x sucesses on n repeated trials, with p probability.
The expected value of the binomial distribution is:
The standard deviation of the binomial distribution is:
Stereo speakers are manufactured with a probability of 0.1 of being defective
This means that
Twenty speakers are randomly selected.
This means that
Let the random variable X be defined as the number of defective speakers. Find the expected value and the standard deviation.
The expected value of X is 2 with a standard deviation of 1.34.
This is problem of ratio and proportion. to solve this, fisrt is calculate the convertion factor.
so the house is 30 feet in actual and 4 in wide on drawing
30 feet / 4 in = 7.5 feet / inso in every inch in the drawing is equivalent to 7.5 feet on actual.
1.2 in ( 7.5 ft/ in) = 9 ft
1.6 in ( 7.5 ft/ in) = 12 ft
<span>(-4,0) and (0,-6) is the answer</span>