Final Exam Stats

Consider the "Age" variable Age 18,18,16,19,19,18,18,19,45 Find the following: IQR:

1

The following frequency distribution summarizes the ages in years of children attending a recent movie at a local theater. Use the following frequency table to answer the next question. Age Freq. 7.5-9.5 18 9.5-11.5 30 11.5-13.5 12 13.5-15.5 6 What is the estimated mean age? (Please round to two decimal places)

10.68

Consider the "Age" variable Age 18,18,16,19,19,18,18,19,45 Find the following: Lower Fence:

16.5

Consider the "Age" variable Age 18,18,16,19,19,18,18,19,45 Find the following: Median:

18

Consider the "Age" variable Age 18,18,16,19,19,18,18,19,45 Find the following: Q1:

18

Consider the "Age" variable Age 18,18,16,19,19,18,18,19,45 Find the following: Q3:

19

Consider the "Age" variable Age 18,18,16,19,19,18,18,19,45 Find the following: Upper Fence:

20.5

Find the average of the the "Age" variable (Round to two decimal places) Age 18,18,16,19,19,18,18,19,45

21.11

A 2012 Gallup survey interviewed by phone a random sample of 474,195 U.S. adults. Participants were asked to describe their work status and to report their height and weight (to determine obesity based on a body mass index greater than 30). Gallup found 24.9% obese individuals among those interviewed who were employed (full-time or part-time by choice), compared with 28.6% obese individuals among those interviewed who were unemployed and looking for work. What is the Statistic in this scenario

24.9%

Suppose in a class of 60 students 5 have no siblings, 26 have one sibling, 14 have two siblings, and 15 have three siblings. Calculate the relative frequency of students who have three siblings. (please express as a percentage)

25

Suppose in a class of 70 students 10 have no siblings, 17 have one sibling, 24 have two siblings, and 19 have three siblings. Calculate the relative frequency of students who have two siblings. (please express as a percentage)

34

Do there appear to be any outliers contained in this sample of the "Number of Moles" variable? Use the fence rule to identify any and enter it as your answer. Moles on Right Hand 11, 19, 8, 15, 10, 24, 20, 40, 1, 17 Note: If you believe there is (are) no outlier(s) enter 0 for your answer

40

Suppose your Test score ranks 14th best out of the 45 students in your class. What Percentile would your quiz grade fall in? (please express as a percentage)

68th

Suppose your Quiz 1 score ranks 8th best out of the 40 students in your class. What Percentile would your quiz grade fall in? (please express as a percentage)

80th

The following frequency distribution summarizes the ages in years of children attending a recent movie at a local theater. Use the following frequency table to answer the next question. Age Freq. 7.5-9.5 18 9.5-11.5 30 11.5-13.5 12 13.5-15.5 6 What is the relative frequency of the 13.5-15.5 Age group? (Express as a percentage)

9

What is the Standard Deviation of the "Age" variable? (Round to two decimal places) Age 18,18,16,19,19,18,18,19,45

9.0062

The weight in pounds of a male child at a certain age has a mean and a standard deviation of 72 pounds and 11 pounds, respectively. How much must a male child at this age weigh for his weight to be "unusually" large? More than _____ LBs

94

A 2012 Gallup survey interviewed by phone a random sample of 474,195 U.S. adults. Participants were asked to describe their work status and to report their height and weight (to determine obesity based on a body mass index greater than 30). Gallup found 24.9% obese individuals among those interviewed who were employed (full-time or part-time by choice), compared with 28.6% obese individuals among those interviewed who were unemployed and looking for work. What is the population in this scenario?

All U.S Adults

What does a z-score tell us? A. how far from the mean given observation is in units of standard deviation B. How unusual an observation is in comparison to the rest of its distribution C. If a given observation is less than or equal to the mean.

All of the above

Which of the following statements about bar charts is true? It sometimes doesn't matter in which order you place the bars representing different categories It is appropriate to have gaps between the bars on the graph. On a bar chart, the width of the bars has no meaning

All of the above

Consider this cross section of data from a hypothetical sample of students. Match the variables to the correct classification of data type. Class Height (in) Cell Provider Moles on Right Hand Freshman-63-T-Mobile-11 Junior-62-Verizon-19 Sophomore-74-Verizon-8 Freshman-64-ATT-15 Freshman-66-T-Mobile-10 Sophomore-63-Verizon-24 Freshman-65-Sprint-20 Sophomore-72-Verizon-36 Freshman-69-Verizon-1 Junior-68-ATT-17 Cell Provider:

Categorical and Nominal

Match the variable with the type of data it would create Home Age Siblings Class NoVA 18 2 Freshman SW VA 18 1 Sophomore The 757 16 0 Freshman Out State 19 4 Freshman Out State 19 1 Senior The 757 18 1 Freshman NoVA 18 0 Junior Out State 19 2 Freshman SWVA 45 3 Sophomore Home:

Categorical and Nominal

Consider this cross section of data from a hypothetical sample of students. Match the variables to the correct classification of data type. Class Height (in) Cell Provider Moles on Right Hand Freshman-63-T-Mobile-11 Junior-62-Verizon-19 Sophomore-74-Verizon-8 Freshman-64-ATT-15 Freshman-66-T-Mobile-10 Sophomore-63-Verizon-24 Freshman-65-Sprint-20 Sophomore-72-Verizon-36 Freshman-69-Verizon-1 Junior-68-ATT-17 Class:

Categorical and Ordinal

Match the variable with the type of data it would create Home Age Siblings Class NoVA 18 2 Freshman SW VA 18 1 Sophomore The 757 16 0 Freshman Out State 19 4 Freshman Out State 19 1 Senior The 757 18 1 Freshman NoVA 18 0 Junior Out State 19 2 Freshman SWVA 45 3 Sophomore Class:

Categorical and Ordinal

What would be the best way to describe the center or most "typical value" for the following histogram?

Data is bimodal, two typical values- 20 and 60

Evaluate the Statements: Statement 1: We can always see outliers show up on a Histogram

False

Evaluate the Statements: Statement 2: The shape of a distribution is always most apparent in a Boxplot

False

Consider the following distribution: The most appropriate measure of spread for this distribution would be:

IQR

Consider the information you have previously calculated about the "Age" variable Age 18,18,16,19,19,18,18,19,45 What would be the most appropriate measures of spread to describe the "Age" variable?

IQR

Assume the number of times a student checks their Instagram has a mean of 15 and standard deviation of 5. Also the number of times a student checks TIkTok has a mean of 10 and standard deviation of 3. Both distributions have a unimodal, symmetric, bell-shaped distribution. What is more "unusual", that a student checks their Instagram 25 times in one day or their TikTok 7 times? A. TikTok 7 times B. Instagram 25 times in one day

Instagram 25 times in one day

Of the two Bar Charts pictured, which shows more variability? Left or Right

Left

Consider the following distribution: The shape of this distribution can best be described as:

Left Skewed

Consider the following distribution: For this distribution the Mean is most likely ______ ________ than the median

Less Than

Parking at a university has become a problem. University administrators are interested in determining the average time it takes a student to find a parking spot. An administrator inconspicuously followed 130 students and recorded how long it took each of them to find a parking spot. What type of graph should NOT be used to display the information collected concerning the students' parking times

Pie Chart

Consider this cross section of data from a hypothetical sample of students. Match the variables to the correct classification of data type. Class Height (in) Cell Provider Moles on Right Hand Freshman-63-T-Mobile-11 Junior-62-Verizon-19 Sophomore-74-Verizon-8 Freshman-64-ATT-15 Freshman-66-T-Mobile-10 Sophomore-63-Verizon-24 Freshman-65-Sprint-20 Sophomore-72-Verizon-36 Freshman-69-Verizon-1 Junior-68-ATT-17 Height:

Quantitative and Continuous

Match the variable with the type of data it would create Home Age Siblings Class NoVA 18 2 Freshman SW VA 18 1 Sophomore The 757 16 0 Freshman Out State 19 4 Freshman Out State 19 1 Senior The 757 18 1 Freshman NoVA 18 0 Junior Out State 19 2 Freshman SWVA 45 3 Sophomore Age:

Quantitative and Continuous

Consider this cross section of data from a hypothetical sample of students. Match the variables to the correct classification of data type. Class Height (in) Cell Provider Moles on Right Hand Freshman-63-T-Mobile-11 Junior-62-Verizon-19 Sophomore-74-Verizon-8 Freshman-64-ATT-15 Freshman-66-T-Mobile-10 Sophomore-63-Verizon-24 Freshman-65-Sprint-20 Sophomore-72-Verizon-36 Freshman-69-Verizon-1 Junior-68-ATT-17 Number of Moles:

Quantitative and Discrete

Match the variable with the type of data it would create Home Age Siblings Class NoVA 18 2 Freshman SW VA 18 1 Sophomore The 757 16 0 Freshman Out State 19 4 Freshman Out State 19 1 Senior The 757 18 1 Freshman NoVA 18 0 Junior Out State 19 2 Freshman SWVA 45 3 Sophomore Siblings:

Quantitative and Discrete

Consider the information you have previously calculated about the "Age" variable Age 18,18,16,19,19,18,18,19,45 If we were to make a histogram of the "Age" variable, what would its shape most likely be?

Right Skewed

Assume the number of times a student checks their Facebook has a mean of 12 and standard deviation of 3. Also the number of times a student checks SnapChat has a mean of 20 and standard deviation of 5. Both distributions have a unimodal, symmetric, bell-shaped distribution. What is more "unusual", that a student checks their Facebook 15 times in one day or their Snapchat 10 times? A. SnapChat 10 times B. Facebook 15 times in one day

Snapchat 10 times

The SAT and ACT readiness tests for college supposedly measure the same thing and both have symmetric, unimodal, and bell-shaped distributions. Students' SAT scores typically have μ= 1509 and σ= 321 while ACT scores typically have μ= 21.5 and σ= 5.4. If student A scores 1820 on the SAT and student B scores 29 on the ACT who has the higher score when compared to their peers?

Student B

A 2012 Gallup survey interviewed by phone a random sample of 474,195 U.S. adults. Participants were asked to describe their work status and to report their height and weight (to determine obesity based on a body mass index greater than 30). Gallup found 24.9% obese individuals among those interviewed who were employed (full-time or part-time by choice), compared with 28.6% obese individuals among those interviewed who were unemployed and looking for work. What is the sample in this scenario?

The 474,195 U.S Adults

A student organization at a local college posted a poll on its website. After a semester, the results were tallied, and it was found that 95% of the respondents were in favor of raising fees to increase funding for student organizations. This conclusion was based on data collected from 5000 votes cast on the website. Which sampling technique is being used?

Voluntary response sampling

Consider the "Age" variable Age 18,18,16,19,19,18,18,19,45 Find the following: Do we have any potential Outliers?:

Yes, 16 and 45

What does it mean to find the mode of a bar chart?

can be found by finding the bar, or category, with the most observations.

If we see all of our rectangles in a bar chart are about the same height, we can interpret that there is...

high variability in our Categorical Data

Researchers conducted an experiment to determine if children who participate in a new after-school tutoring program do better on state-mandated tests than children who do not attend the program. What is the treatment variable?

participation in the after-school program

Researchers conducted an experiment to determine if children who participate in a new after-school tutoring program do better on state-mandated tests than children who do not attend the program. What is outcome variable?

test score on the state-mandated test.

Researchers conducted a study and determined that elementary students who carpool have fewer friends than students who ride the bus to school. Parents ask can we conclude that carpooling causes students to have fewer friends? Why is the answer no?

this is an observational study and we cannot conclude causation.

In a physical fitness class of 81 students, each student's percentage body fat is measured at the beginning & end of the semester. The instructors of the course want to see if student's body composition changed. What experiment design is being implemented here?

Matched Pairs

A boxplot can show us all of the following about our data set except:

Mean

Consider the following distribution: The most appropriate measure of center for this distribution would be:

Mean

Consider the information you have previously calculated about the "Age" variable Age 18,18,16,19,19,18,18,19,45 What would be the most appropriate measures of center to describe the "Age" variable?

Median

Which of the following descriptive measures is most robust, or resistant to outliers and extreme values? Mean, Standard Deviation, Median, Range

Median

What does it mean for an experiment to be double-blinded?

Neither the researcher nor the participants know who is in the treatment and control groups.

Researchers conducted a study and determined that elementary students who carpool have fewer friends than students who ride the bus to school. Can we conclude that carpooling causes students to have fewer friends?

No