Unit 1 + 2
Unit 3 + 4
Unit 5 + 6
Unit 7
Risky...
100
Which graphical display is most appropriate for representing quantitative data?
1. Bar Graph
2. Histogram
3. Pie Chart
4. Line Plot
Histogram
100
Kristen is investigating the opinions of students at her high school on the new school hours proposed by the school board. Which of the following is her population of interest?
a. All students in her high school
b. students with busy schedules
c. students and teachers
d. students in her classes
a. All students in her high school
100
relative frequency
(the # of times an event was observed to occur)/(the total observations)
100
How can you reduce the variability of a statistic?
bigger sample size
better design (stratified sampling)
100
Which teacher at our school has human bones from Tennessee?
Miss.Reuscher
200
When adding or subtracting a constant to each value of data, which summary statistic will remain unchanged?
1. Mean
2. Median
3. Percentiles
4. Standard Deviation
Standard Deviation
200
The manager of a shopping mall distributed a customer-satisfaction survey by handing it to people as they came through one of the doors to the mall one day. Of those handed out, 215 were completed and returned. Should the results of the survey be generalized to the population of all customers of the shopping mall?
No, because a random sample from all customers of the shopping mall was not selected.
200
define: discrete random variable and continuous random variable
discrete: a random variable with a discrete # of outcomes (rolling a dice)
continuous: a random variable that is not countable (area under a normal curve)
200
What is the difference between accuracy and precision?
accurate = unbiased
precise = low variability
200
Congratulations, FREE POINTS
1,604 students
400
Before sending track and field athletes to the Olympics, the U.S. holds a qualifying meet.
The upper dot plot shows the distances (in meters) of the top shot putters in the preliminary round of the Olympic games. The lower dot plot shows the top throwers in the shot put at the U.S. qualifying meet.
Distance (meters)Olympic preliminary U.S. qualifier
Which pieces of information can be gathered from these dot plots?
Choose all answers that apply:
- (Choice A)
The top Olympic shot putters in the preliminary round threw farther on average than the top U.S qualifiers.
- (Choice B)
The distances of the top Olympic shot putters vary noticeably more than those of the top U.S. qualifiers.
- (Choice C)
None of the above
A
The top Olympic shot putters in the preliminary round threw farther on average than the top U.S qualifiers.
400
A medical researcher is conducting clinical trials. Of the 60 people participating in the trial, 20 will receive a placebo, 20 will receive the experimental drug, and 20 will constitute the control group. The 20 people who will receive the drug will be selected at random.
Briefly explain why your assignment strategy is important in assessing the effectiveness of the clinical trial.
The randomization for selecting individuals to receive the experimental drug...
- prevents the selection bias in treatment assignments
- helps the sample be representative of the population
400
A town council wants to estimate the proportion of residents who are in favor of a proposal to upgrade the computers in the town library. A random sample of 100 residents was selected, and 97 of those selected indicated that they were in favor of the proposal. Is it appropriate to assume that the sampling distribution of the sample proportion is approximately normal?
No, because the sample is not large enough to satisfy the normality conditions.
400
A random sample of mice is obtained, and each mouse is timed as it moves through a maze to a reward treat at the end. After several days of training, each mouse is timed again. The data should be analyzed using
A. a z-test of proportions.
B. a two-sample test of means.
C. a paired t-test.
D. a chi-square test.
E. a regression analysis.www.crackap.com
C. a paired t-test
400
Who, with 32 Grammys, has broken the record for the most Grammys?
Beyonce
600
What is a variable other than x & y that simultaneously affects both variables and accounts for the correlation between the two?
lurking variables - variables that weren't included in a study but that influence both included variables, the independent and dependent variables
600
BatCo, a company that sells batteries claims that 95.5% of their batteries are in working order. How many batteries would you expect to buy on average to find one that does not work?
a. 5
b. 10
c. 200
d. 995
e. 2000
C.) 200
1−p=1−0.995=0.005
The expected value of a geometric distribution is given by 1/1-p.
So, 1/0.005=200.
600
Question below is based on the following: To study the relationship between party affiliation and support for a balanced budget amendment, 500 registered voters were surveyed with the following results:
What percentage of those surveyed were for the amendment and were Republicans?
A. 25%
B. 38%
C. 40%
D. 62.5%
E. 65.8%
A. 25%
125/500
600
A disc jockey wants to determine whether middle school students and high school students have similar music tastes. Independent random samples are taken from each group, and each person is asked whether he/she prefers hip-hop, pop, or alternative. A chi-square test of homogeneity of proportions is performed, and the resulting P-value is below 0.05. Which of the following is a proper conclusion?
A. There is sufficient evidence that for all three music choices the proportion of middle school students who prefer each choice is equal to the corresponding proportion of high school students.
B. There is sufficient evidence that the proportion of middle school students who prefer hip-hop is different from the proportion of high school students who prefer hip-hop.
C. There is sufficient evidence that for all three music choices the proportion of middle school students who prefer each choice is different from the corresponding proportion of high school students.
D. There is sufficient evidence that for at least one of the three music choices the proportion of middle school students who prefer that choice is equal to the corresponding proportion of high school students.
E. There is sufficient evidence that for at least one of the three music choices the proportion of middle school students who prefer that choice is different from the corresponding proportion of high school students.
E. There is sufficient evidence that for at least one of the three music choices the proportion of middle school students who prefer that choice is different from the corresponding proportion of high school students.
600
YOU JUST LOST POINTSSSSSSSSSSS hehe
sorry queen
800
A class of 30 students takes a math test. The scores are summarized as follows:
- Mean score: 75
- Standard deviation: 10
a) How would you construct a boxplot to display the distribution of scores.
b) Calculate the interquartile range (IQR) of the scores.
a) To construct a boxplot, first, calculate the quartiles: Q1 = 67.5, Q2 (median) = 75, Q3 = 82.5. Then, determine the lower and upper fences: Lower fence = Q1 - 1.5 * IQR, Upper fence = Q3 + 1.5 IQR. Finally, plot the boxplot with the median line inside the box, the box representing the IQR, and the whiskers extending to the fences.
b) IQR = Q3 - Q1 = 82.5 - 67.5 = 15.
800
Consider rolling two number cubes, each of which has its faces numbered from 1 to 6. The cubes will be rolled and the sum of the numbers landing face up will be recorded. Let the event E represent the event of rolling a sum of 5. How many outcomes are in the collection for event E ?
4
800
What method do you use to check if a distribution or probability is binomial?
BINS:
1. Binary: There only two outcomes (success and failure)
2. Independent: The events independent of one another?
3. Number: There is a fixed number of trials
4. Success: The probability of success equal in each trial
800
10. Random samples of 25 students are chosen from each high school class level, students are asked whether or not they are satisfied with the school cafeteria food, and the results are summarized in the following table:
Is there sufficient evidence of a difference in cafeteria food satisfaction among the class levels?
A. The data prove that there is a difference in cafeteria food satisfaction among the class levels.
B. There is sufficient evidence of a linear relationship between food satisfaction and class level.
C. There is sufficient evidence at the 1% significance level of a difference in cafeteria food satisfaction among the class levels.
D. There is sufficient evidence at the 5% significance level, but not at the 1% significance level, of a difference in cafeteria food satisfaction among the class levels.
E. With P = 0.1117 there is not sufficient evidence of a difference in cafeteria food satisfaction among the class levels.
E. With P = 0.1117 there is not sufficient evidence of a difference in cafeteria food satisfaction among the class levels.
800
How long was the shortest war?
38 minutes...