Question

1. Following a normal probability distribution with a mean of 200 and a standard deviation of 10, 95 percent  of the population will be between:

		200 and 220
		180 and 220
		180 and 200
		less than 180

3. A family of four spends an average of $1000 per month with a standard deviation of $50.  This spending follows a normal continuous distribution.  

What is the probability that a family will spend more than $1050 in a month?  (answer to 3 decimal places)

5. If two events, A and B, are mutually exclusive, then P(A or B) = P(A) + P(B) - P(A&B)

True

False

6. A coin is tossed 8 times.  It is a fair coin with 2 sides, heads and tails.  What is the probability that in 8 tosses, 7 or less will be flipped?

		0.996
		0.004
		1
		0.5

7. Following a normal probability distribution with a mean of 200 and a standard deviation of 10, 68 percent  of the population will be between:

		170 and 230
		190 and 210
		180 and 220
		Greater than 200

Answer 1

1. Here it is given that distribution is normal with mean=200 and standard deviation=10

We need to find 95 percent of the population will lie between what values

As we know as per 68-95-99 rule Approximately 68% of the data fall within one standard deviation of the mean. Approximately 95%of the data fall within two standard deviations of the mean. Approximately 99.7% of the data fall within three standard deviations of the mean.

So data fall within two standard deviations of the mean will have 95 percent and that can be obtained from the values between

180 and 220 3. Here distribution is normal with mean=1000 and standard deviation=50 We need to find As distribution is normal we can convert x to z 5. For mutually exclusive events Hence answer is False 6.Here distribution is binomial with p=0.5 and n=8

7. As we know as per 68-95-99 rule Approximately 68% of the data fall within one standard deviation of the mean. Approximately 95%of the data fall within two standard deviations of the mean. Approximately 99.7% of the data fall within three standard deviations of the mean.

So data fall within one standard deviations of the mean will have 68 percent and that can be obtained from the values between

190 and 210