Topics 1/3/4
Topics 5/6
Topics 8/10/11
Topic 13, 15, 16
Probability
100
Is the variable qualitative, quantitative, or constant? If qualitative, is it binary:
Height of students in the class
Quantitative
100
According to the Empirical Rule, approximately what percent of data is within 2 standard deviation from the mean?
95%
100
Describe the correlation (strength and direction)
mod-strong negative
100
A medicinal study of the effect of meditation on memory is being conducted. Participants take a memory test in the morning and at night. One group is meditating during the day, and one is not meditating during the day.
Which is the explanatory variable and which is the response variable?
Explanatory: meditation (yes or no)
Response: memory test results
100
There are 8 marbles in a bag, 4 red, 3 green and 1 blue. What is the probability of picking a green marble and then a blue without replacement?
3/56=.05367=5.4%
(3/8)(1/7)=3/56
200
Is the variable qualitative, quantitative, or constant? If qualitative, is it binary:
Score of highest grade on the Unit Test
Constant
200
Which Brand has the smallest IQR?
Brand B
200
What would the correlation coefficient (r value) be for a scatterplot with a strong positive correlation?
anything above .8
200
IQ scores generally follow a normal distribution with a mean of 100 and a standard deviation of 16.
What percent of people’s IQs would you expect to be under 90?
.2643
zscore=-.625=-.63
200
Find the number of 3 person teams you can create from a group of 8 people.
56
8C3
300
Give an example of a qualitative, binary, variable.
passing test. attending school/not attending school.
300
If the data set is skewed left, what would be a better measure of center, mean or median? AND WHY?
Median, it is resistant to outliers where the mean will be less than the median.
300
A regression line shows the negative relationship between time in seconds (x-axis) and score for winning a game of Solitare (y-axis). The equation of the regression line is y=-20x+8200.
What does the y-intercept mean in terms of this context?
If you complete the game in 0 seconds, you earn a score of 8200
300
IQ scores generally follow a normal distribution with a mean of 100 and a standard deviation of 16.
What score do the top 10% of people score?
120.48
.8897->1.28=(x-100)/16
20.48=x-100
300
How many distinguishable ways can the letters in the word ONOMATOPOEIA be written?
9,979,200
12!/(4!2!)
400
Given the 5 number summary, is there an outlier? If so, what?
min: 1 Q1: 9 Med: 12 Q3: 15.25 Max: 26
yes, the max is an outlier
400
Jill scored a 85% on her math test and Bill scored a 90% on his math test. If Jill's test had an average of 88% and a standard deviation of 2, while Bill's test had an average of 93 with a standard deviation of 1.25, who did better on their exam comparatively?
Jill! Her z-score is -1.5. Bill's z-score is -2.4.
400
A regression line shows the negative relationship between time in seconds (x-axis) and score for winning a game of Solitare (y-axis). The equation of the regression line is y=-20x+8200.
What does the slope mean in terms of this context?
For every additional second played, you lose 20 points from your score.
400
Consider the population of Reese's Pieces. It's advertised that the brown color appears 35% of the time. If the standard error is approximately .052, fill in the blanks:
According to the CLT, the sample proportion of brown Reese's Pieces will vary by about ___% from the mean of ____%.
will vary about 5.2% from the mean of 35%
400
Using the digits 3, 4, 5, 6, and 7, how many even 3 digit numbers can be formed such that there are no repeating digits in the number?
24
4*3*2
500
What is wrong with this stem and leaf plot?
There is no key included!
500
A manufacturer of calculators keeps track of length of time it takes before a product is returned for repair. They find the mean is 985 days and the standard deviation is 83 days. What percentage of calculators need to be repaired between 902 and 1151 days?
81.5%
95-68=27/2=13.5
68+13.5=81.5
500
A regression line shows the negative relationship between time in seconds (x-axis) and score for winning a game of Solitare (y-axis). The equation of the regression line is y=-20x+8200.
If the actual score for a game of solitaire finished in 350 seconds is 1287, what is the residual? (hint: find the predicted first)
87 points
actual - predicted
1287-1200
500
Consider taking a random sample of 100 from a population of M&Ms. It's advertised that the blue color appears approximately 20% of the time.
Calculate the standard error
SE=sqrt((p(1-p))/n)
.04=4%
sqrt(((.2)(.8))/100
500
Jeff hangs out with his friends 45% of the time on Saturdays. If Jeff hangs out with friends, the probability of him eating dinner with them is 60% and if he does not hang out with them, the probability of him eating dinner with them is 10%.
What is the probability that Jeff will hang out with his friends and not eat dinner with them?
18%
1-.6=.4
(.45)(.4)=.18