Lake Braddock MiniSO Invitational — Experimental Design

A youth soccer league has 15 teams. Bobbo surveys each member of three of the teams to ask what the best pregame meal is.

Jimbo wants to figure out what the most popular sport in the country is. He decides to take this sample by asking the first 100 people he sees at a baseball game. What a fool!

Annie wants to see what her peers thought of the previous night's student council debate. She finds a list of each student and organizes the students by birth date. She asks every 17th student by bithdate who they thought won the debate.

James Kim is determined to figure out how much sleep the average student at his school gets. He knows that each student has a 3rd period class, so he decides to create of sample poll of 5 students from each 3rd period class, selected by a simple random sample.

Josh Gao, being the professional Science Olympiad analyzer that he is, wants to find out once and for all what the best Science Olympiad event is. He uses a random number generator to choose 12 teams attending the LB Invite, from which he'll ask each team member. ( tiebreaker )

Remy wants to know what people think of his gluten free gourmet soup, but he only want the opinion of people who have had gourmet soups with gluten before. He surveys each of his customers about his gourmet soup, but his first question is "have you had a gourmet soup with gluten before?" Anyone who answers "no," he disregards as part of his sample.

What's the difference between quota and stratified sampling?

Sam works at Sam's club handing out samples of Snapple. Sam wants to know the best flavor of Snapple, but needs a sample of the population of Sam's club samplers to conduct his experiment. Sam's samplers sample three different flavors of Snapple. He knows he has 600 samplers of Snapple a day and he wants 100 samplers in his sample, so in order to create his sample population Sam's samplers roll a die, and Sam only asks the sampler's favorite flavor if they roll a 3. This way he can ensure he will have 100 people in his sample since the odds of a 3 are 1/6. The samplers for whom Sam rolls a 3 are now his sample. What method of choosing a sample population does Sam most closely exhibit?

What are two errors with Sam's method of creating a sample for his study?

Which of the following sampling methods is most commonly part of a multistage probability sample?

A sampling error refers to a fault in the method of selecting a sample of the population.

A non-sampling error refers to errors that are unavoidable in a study due to the inability to survey an entire population.

Non-sampling errors may include mistakes in data collection.

Systematic and random errors are most commonly discussed in reference to...

What is the best way to reduce the effect of sampling errors (0.5)? Why is this the best method (0.5)?

Which of the following are symbols for statistics?

Why did you choose the symbols you did in the previous question?

Professor Flynn is grading tests for her Intro to Quantum Boogaloo class, and finds that the mean score is 42.0%. She creates a data plot of the scores and treats the mean of 37.5 a the "true value". She pulls four scores at random and determines that the are exactly accurate to the class mean but are not precise. Give an example of four scores that could match this description.

Erik decides to play some basketball but is a little rusty. All of his shots miss and hit the top right corner of the backboard. How would you describe Erik's shots in terms of precision and accuracy?

Buford and Baljeet are doing test corrections for their 5th grade statistics class. Baljeet, as usual, has no corrections to make so he is helping Buford. The first question says, "You repeatedly roll 100 fair, 10 sided dice out of a bag and each time count the number of 2s that appear. The first four trials have results of 8, 11, 8, and 9 for the number of 2s. What is the mean number of 2s in this sample?" Buford answers 8. What is the correct answer and what measure did Buford express?

Baljeet shakes his head in dismay and moves on to the next question which reads, "Use the law of large numbers to determine what that mean will approach as the process repeats, and explain why." Buford had pondered this question for minutes but ultimately accepted defeat and just wrote 8 . "NOooOOOooo!" Baljeet exclaims. "You can't just write the same number but LARGER!!" What should Buford have said?

Isabella strolls over to Buford and Baljeet to ask what they're doing. Baljeet casually flexes his perfect test and says he's helping Buford. "What about this one," Isabella says as she points to a X on the third page bonus question. The bonus question said, "If the first set of trials consistently produce a mean higher than the expected, why will the mean eventually be lowered?" Baljeet, in a brief lapse in judgment, wrote, "because the initial results were higher, the probability of the result being observed will be lower in successive trials." Isabella, who consistently aces the tests but just isn't as cocky about it, explains the correct answer. What was the mistake Baljeet made, and what was the correct answer?

In words, what does the expression for the Weak Law of Large Numbers state?

Provide an example of a two values that may correlate but do not have a causative relationship

What must be done to prove that causation exists between two values/events?

Which of the following is most commonly the reason for a situation where there is correlation without causation between two values?

What is the general term for events that are correlated but not causally related?

If data between x and y shows a best fit line that is a straight, horizontal line, there is still a correlation between these two variables.

It is possible to have causation without noticeable correlation.

Explain your answer to the previous question (through reasoning and give an example (.5 points each).

Saying that correlation implies causation would be a _ _ _ _ _ _ _ _ _ _ _ _ - _ _ _ _ _ logical fallacy. (This question is not auto graded so don't worry about formatting)

What types of data are in data tables?

The y-axis of a graph represents the ____, while the x-axis of a graph represents the ____.

What is the type of graph depicted above? Explain the dip from around 5-20?

What's another name for a Mosaic chart (.5 points)? Also, answer either... (.5 points) -what is the purpose of a mosaic chart or

• what does a mosaic chart look like You will not get bonus points for answering both.

What would be the purpose of making a bar chart stacked as opposed to regular? Provide an example of when you could use one.

You're measuring what the percentage of people that enjoy eating each of 5 different kinds of food. When displaying your data you want to be as concise as possible. Should you use a pie chart or bar graph. Why?

Jenna bought different flavors of popsicles for her party in packs of 3, 6, 8, 3, 5, 8, 6, 9, 6, 3, and 5. What is the mode?

How would you classify Jenna's data set in terms of the mode (1 word)?

Luna scored 63, 53, 67, 42, and 91 on her pre-assessments at the beginning of the school year. What is the mean?

What is the range of 54, 23, 61, 58, 64, 36, 51, 35, 26, and 29?

Find the median of the following values: 24, 83, 39, 18, 91, and 44.

The number of people in a school's orchestras are 27, 19, 28, 30, 27, 42, 68, and 61. Determine the mean.

The number of people in a school's orchestras are 27, 19, 28, 30, 27, 42, 68, and 61. Determine the range.

The number of people in a school's orchestras are 27, 19, 28, 30, 27, 42, 68, and 61. Determine the mode.

The number of people in a school's orchestras are 27, 19, 28, 30, 27, 42, 68, and 61. Determine the median.

Create a data set of at least five values that has a range, median, mode, and mean that are all equal, but has a standard deviation that does not equal 0.

Create a data set that has σ=0.5 ( tiebreaker )

Given that the first four data points are 1, 3, 5, and 2, finish the data set so the mode equals 37 and the mean equals 14.

Heinz is doing recon on the platypus population in the the tri-state area and wants to know the standard deviation of the masses of platypuses in the tri-state area. He finds 10 platypuses and believes them to account for all of the platypus population in the tri-state area, and finds the standard deviation of their masses to be 13.2 grams. He soon finds out that there's a whole plethora of platypuses in the suburbs of the tri-state area, so he has to recalculate his standard deviation as those ten platypuses are only a sample. What is the new standard deviation? ** **

What is measured using the 1.5 IQR rule, and how do you conduct that test?

You're measuring the height of your bean plants for your horticulture event. The heights of the bean plants in centimeters are 19, 22, 50, 2, 31, 27, 26. Make a claim using the 1.5 IQR rule and explain your work.

Generally, if many trials are conducted, will systematic or random errors produce a result that is closer to the true value? Why?

How will repeated trials reduce the effect of systematic error in an experiment?

If significant random error is introduced into an experiment, explain how a graph of the distribution of values would be transformed from the graph if no significant random error was included.

Why are subjects required to fast before taking a blood test? Describe the possible errors in the data if subjects did not fast before blood testing.

Describe greatest possible error, and give an example using a standard measurement instrument.

An experiment determined that the atomic mass of AlCl was 60.24 g/mol, however, the accepted atomic mass of AlCl is 62.43 g/mol. Calculate the percent of error. ( tiebreaker )

An experiment determined that the density of silver (Ag) was 11.58 g/cm³, however, the accepted density of silver (Ag) is 10.49 g/cm³. Calculate the percent of error.

Estimates of uncertainty are always rounded down.

In a research study determining the average weight of different regions in the United States, subjects were not required to take off clothes before measuring in some testing facilities while subjects were required to take off clothes before measuring in other testing facilities. Is this an example of systematic error or random error? Why?

Random error primarily affects the ____ of a data set ( tiebreaker )

Height measurements vary due to changes in posture. Is this an example of systematic error or random error? Why?

In a middle school lab, students measured the pressure of gas in a container, however, one of the students realized that the container had tiny holes. How would this affect the data and is this a systematic or random error?

An error in calibration of a spectrophotometer leads to a consistently lower absorbance for each of the solutions measured in an experiment. Is this an example of systematic error or random error? Why?

Jessica is testing the mass of different substances of the same volume in order to determine density but she realizes after measuring all the substances that she forgot to zero the scale for the cup. How was the density of the substances affected? Is this an example of systematic error or random error?

Why is it important to recognize systematic and random errors in data?

How does adding a lower outlier affect a data set?

Identify any outliers in the data set: 1, 27, 43, 44, 78