WorksheetsG 11 ASP - SBQ 4
Total questions: 20
Worksheet time: 48mins
The mean amount of time to mix the batter for a cake is 14 minutes with a standard deviation of 2.5 minutes. The mean amount of time to bake the cake is 35 minutes with a standard deviation of 6.2 minutes. What is the mean time to make and bake a cake? What is the standard deviation?
mean = 49 min sd = 8.7 min
mean = 49 min sd = 6.685 min
mean = 21 min sd = 8.7 min
mean = 21 min sd = 6.685 min
The mean hourly salary for a high school graduate is $13.50 per hour with a standard deviation of $5.75. The mean hourly salary for a person with an Associate's degree is $19.75 with a standard deviation of $9.25. What is expected difference in the hourly salaries between a high school graduate and a person who earned an Associate's degree?
$33.25
$-3.50
$-6.25
$15.00
The mean weight of a bag checked in at Southwest Airlines is 36 pounds with a standard deviation of 3.5 pounds. If two random bags were checked, what is the mean and the standard deviation of the weights of the two bags?
36, 4.95
36, 7
72, 4.95
72, 7
The mean weight of a dog is 34 pounds with a standard deviation of 6.7 pounds. The mean weight of a cat is 12 pounds with a standard deviation of 3.1 pounds. If you have 2 dogs and 1 cat, what is the mean and standard deviation of their total weight?
80, 9.969
80, 16.5
46, 7.382
46, 16.5
Which of the following is the expected value of X?
Find the missing value for P(X=5) in the probability ditribution:
Number of Toys | Probability
0| 0.03
1| 0.16
2| 0.30
3| 0.23
4| 0.17
5| ?
0.11
0.21
0.01
0.31
X 50 20 5
P(X) 0.1 0.3 0.6
A random variable X has a mean of 120 and a standard deviation of 15. A random variable Y has a mean of 100 and a standard deviation of 9. If X and Y are independent, approximately what is the standard deviation of X – Y?
24.0
17.5
12.0
6.0
4.9
When you add a positive constant to a random variable the effects on the random variables distribution are as follows:
the shape is changed, the mean is increased by a value of "a" and the standard deviation is unchanged.
the shape and standard deviation are unchanged and the mean is increased by a value of "a".
all three aspects are unchanged
the shape and mean are unchanged and the standard deviation is increased by a value of "a".
Multiplying a random variable by a positive constant "b" affects the distribution of the random variable as follows:
the shape is unchanged, measures of center and spread, both, are multiplied by "b".
the shape, measures of center and measures of spread are all multiplied by "b".
the shape and measures of center are unchanged, the measures of center are multiplied by "b".
there is no change in the distribution.
The variance of the sum or difference of two independent random variables is ________________.
found by adding the two variances
found by adding or subtracting the two variances
A random variable is defined by a rule that assigns a _______________ to every outcome in a sample space.
number
letter
Event
probability
Let Y = the # of cups of lemonade that Jill sells at her lemonade stand in one hour. If she sells the cups of lemonade for $2.50 each, what is the standard deviation of the amount of money she makes in an hour?
$5
$6.58
$2.40
$25
Let Y = the # of cups of lemonade that Jill sells at her lemonade stand in one hour. If she sells the cups of lemonade for $2.50 each, how much money does she expect to make in an hour?
$5
$6.58
$2.40
$25
