Unit 1
What is the mode of this data set?
7, 4, 7, 2, 7, 3, 7, 8, 6, 7, 7, 4, 7, 3, 7
7
Which measure is most resistant to outliers?
(A) Mean
(B) Standard Deviation
(C) Range
(D) Median
D. Median
A school wants to survey students about cafeteria food. Which method is a simple random sample?
(A) Surveying students in the lunch line
(B) Surveying every 5th student entering school
(C) Using a random number generator to select student ID numbers
(D) Surveying only seniors
(C) Using a random number generator to select student ID numbers
2 fair six-sided dice are rolled. What is the probability the sum is 8?
(A) 1/12
(B) 5/36
(C) 1/6
(D) 1/9
(B). 5/36
Which condition is required to use CLT?
(A) Sample must be at least 30
(B) Population must be normal
(C) Random sample
(D) Population must be large
(C) Random Sample
When comparing the distribution of quantitative variables for two groups, it would be best to use relative frequency histograms rather than frequency histograms when _______.
the distributions have different numbers of data values
Which of the following is not important to adress when describing the relationship shown in a scatterplot?
(A) Direction
(B) Center
(C) Unusual features
(D) Strength
B. Center
A TV station asks viewers to call in and vote on their favorite movie. This is an example of:
(A) Simple random sample
(B) Stratified sample
(C) Convenience sample
(D) Voluntary response sample
D. Voluntary response sample
If events A and B are independent. If P(A)= .4 and P(B)= .5, what is P(A n B)?
(A) .2
(B) .45
(C) .9
(D) .1
(A) .2
The mean weight of apples is 150 grams with a standard deviation of 20 grams. If a random sample of 25 apples is taken, what is the standard deviation of the sampling distribution of the sample mean?
(A) 20
(B) 4
(C) 5
(D) 100
(B) 4
0, 1, 2, 3, 4, 5, 6, 7, 8
A dataset has a mean of 50 and a median of 60. Which best describes the shape?
(A) Symmetric
(B) Skewed Right
(C) Skewed Left
(D) Uniform
C. Skewed Left
Why is random assignment important in experiments?
It allows cause and effect conclusions
A card is drawn at random from a standard 52-card deck. What is the probability it is a heart or a king?
(A) 17/52
(B) 16/52
(C) 4/52
(D) 13/52
(B) 16/52
A population has a mean of 80 and a standard deviation of 10. If n= 100, what is the mean of the sampling distribution of -x-?
(A) 10
(B) 100
(C) 1
(D) 80
(D) 80
Mean: 10,614
SD:8049
Min:1873
Max:30,823
Based on the relationship between the mean, standard deviation, minimum and maximum, is it reasonable to believe that the distribution is approximately normal?
It is not approximately normal because the minimum should be about 3 standard deviations below the mean
The heights of students are approximately normally distributed with a mean of 68 inches and a standard deviation of 3 inches. What percentage of students are between 65 and 71 inches?
(A) 34%
(B) 68%
(C) 95%
(D) 99.7%
B. 68%
A survey asks people leaving a gym about their eating habits? What type of bias might occur?
Sampling Bias
If P(A)= .7, what is P(A')?
(A) .7
(B) .3
(C) 1.7
(D) -.7
(B) .3
A bag contains 60% red balls and 40% blue balls. A random sample of 50 balls is taken. Find the mean and SD of P hat.
Mean: .6
SD: .069
Imagine rolling a fair, six-sided die 60 times. Draw a graph of the die rolls. Should you use a bar graph or a histogram to display the data?
A bar graph is used because it deals with discrete categorical data.
The relationship between x= number of wins and y= average attendance per game for Major League Baseball teams has a correlation of r= .56. If the mean attendence is 28,196 with a standard deviation of 9402, what is the predicted attendance for a team whose numbers of wins is 1 standard deviation above average?
(A) 25,192
(B) 28,196
(C) 33,461
(D) 37,598
C. 33,461
A farmer divides his farms into acres and randomly selects some acres to survey all the crops in them. This is:
Cluster sampling
A game costs $2 to play. you have a 25% chance of winning $10 and a 75% chance of winning nothing. What is the expected value of the game?
(A)-$.50
(B) $.50
(C) $2.00
(D)-$2.00
(B) $.50
A company claims the average battery life is 10 hours with a SD of 1.5 hours. A sample of 64 batteries is taken. Find the sample mean and standard deviation.
Mean: 10 hours
Standard Deviation: .1875 hours