Yes you did, congratulations ;-)
Answer:
77966 divided by 12 will give you the answer of 6
For the answer to the question above,
since the only variable used to determine earnings is the number of doors knocked, you can eliminate options 1 and 3 as they are based on the number of books sold, which is not a part of the equation.
That leaves the only options being the increase of $20 or $50 for each door knocked. As the x value we multiply by 20, the correct answer is #2, her earnings will increase by $20 for each door knocked.
You can also check this by plugging in values:
Assume 10 doors are knocked:
E(10) = 20(10)-50 = 200-50 = 150
Assume 11 doors (1 more door) is knocked:
E(11) = 20(11)-50 = 220-50 = 170
<span>The increase from 1 door is $20. the answer is B</span>
You have to add .7+.7+5+5=11.4
A) The empirical rule tells you the probability of being within 1 standard deviation of the mean is 68%.
b) The probability that the sample mean falls within 3 standard deviations* of the mean is 99.7%.
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* The standard deviation of the sample mean is 1/√9 = 1/3 of the standard deviation of an individual sample. Hence the same limits (90-110) now cover 3 standard deviations of the sample mean.