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Math-130 Chapter 1 Review 2020.tst MATH-130 Chapter 1 Review _____________________________________ _______/ 16 = _____________ points Show work for EVERY problem. Show work for multiple choice by explaining why you chose that answer. Points are earned through showing your work and answers. Answers without work shown or explanations will not receive credit. Use critical thinking to determine whether the sampling method appears to be sound or is flawed. 1) A researcher published this survey result: "74% of people would be willing to spend 10 percent more for energy from a non-polluting source". The survey question was announced on a national radio show and 1,200 listeners responded by calling in. What is wrong with this survey? Form a conclusion about statistical significance. Do not make any formal calculations. Either use the results provided or make subjective judgments about the results. 2) Charlie's teacher claims that he does not study and just guesses on exams. On an exam with 201 true-false questions, Charlie answered 53.7% of the questions correctly. Calculations using these results show that if he were really just guessing, there would be roughly 1 chance in 7 that he would do this well. Is there statistically significant evidence against the teacher's claim that Charlie is just guessing? Why or why not? 3) A manufacturer of laptop computers claims that only 1% of their computers are defective. In a sample of 600 computers, it was found that 3% were defective. If the proportion of defectives were really only 1%, there would be less than 1 chance in 1000 of getting such a large proportion of defective laptops in the sample. Is there statistically significant evidence against the manufacturer's claim? Why or why not? Provide an appropriate response. 4) An article stated that last year 807 people taking a certain medication suffered from serious side effects while this year, after the medication had been modified, only 391 suffered serious side effects. What information is missing? Why would it be important to include this information? Solve the problem. 5) On a test, if 115 questions are answered and 41% of them are correct, what is the number of correct answers? A) 53 B) 74 C) -24 D) 47 1 Determine whether the given value is a statistic or a parameter. 6) A sample of 120 employees of a company is selected, and the average age is found to be 37 years. A) Parameter B) Statistic 7) After inspecting all of 55,000 kg of meat stored at the Wurst Sausage Company, it was found that 45,000 kg of the meat was spoiled. A) Statistic B) Parameter Determine whether the given value is from a discrete or continuous data set. 8) The height of 2-year-old maple tree is 28.3 ft. A) Discrete B) Continuous 9) The number of stories in a Manhattan building is 22. A) Continuous B) Discrete Determine which of the four levels of measurement (nominal, ordinal, interval, ratio) is most appropriate. 10) Survey responses of "good, better, best". A) Ordinal B) Ratio C) Nominal D) Interval 11) Ages of survey respondents. A) Interval B) Ratio C) Ordinal D) Nominal 2 Determine whether the given description corresponds to an observational study or an experiment. 12) A marketing firm does a survey to find out how many people use a product. Of the one hundred people contacted, fifteen said they use the product. A) Observational study B) Experiment 13) A sample of fish is taken from a lake to measure the effect of pollution from a nearby factory on the fish. A) Experiment B) Observational study Identify which of these types of sampling is used: random, stratified, systematic, cluster, convenience. 14) A market researcher selects 500 drivers under 30 years of age and 500 drivers over 30 years of age. A) Stratified B) Random C) Cluster D) Systematic E) Convenience 15) A tax auditor selects every 1000th income tax return that is received. A) Convenience B) Cluster C) Systematic D) Random E) Stratified Provide an appropriate response. 16) A teacher at a school obtains a sample of students by selecting a random sample of 20 students from each grade. What kind of sampling is being used here? Will the resulting sample be a simple random sample of the population of students at the school? Explain your thinking. 3 Microsoft Word - In class Working with Graphing Calculators Sp20 1 In class work MATH-013 Graphing Calculator Intro MATH-013 in class work: Name:_____________________ Intro to the graphing calculator: The math department at COTC has required you to purchase a TI-83 or TI-84 for this and other math classes. You are probably wondering why you need this calculator as opposed to another calculator. There are certain things that we are going to study in this and other classes that require graphing. A graph is a “picture” of what an equation looks like. While some functions can be graphed on paper, others would be EXTREMELY cumbersome. This calculator allows us to look at all kinds of functions as well as zoom in and out of the picture to examine some areas of interest. Since you bought this wonderful piece of equipment, it is necessary to learn how to operate this machine. While you will be learning a lot more applications of this calculator in other math classes, including your statistics class, the purpose of this activity is to learn the basics of the calculator. To illustrate why we need to learn how to work with this tool I would like to draw your attention to the following problem. 1) ?ℎ?? ?? ???????? ?ℎ??? ???????? Now I know most of you can do this problem in your head, negative three squared is negative three times negative three, which is going to give you a positive nine. Correct? Well let’s make sure our calculator can actually do multiplication. So press the following keys: So if you entered everything correctly the picture on the right should be the picture your calculator displays. Now let’s press the key and see what this gives us. But wait didn’t we say this was supposed to be positive 9? Does our calculator not know how to do math? Is it broken? This is a perfect example of why we need to learn how to program things into our calculator correctly. I will return to this example later, but let this serve as a guide. If we do not learn how to use this instrument properly, it can lead to confusion. 2 In class work MATH-013 Graphing Calculator Intro 2) Please take about 5 minutes and explore the buttons on the calculator. After 5 minutes we are going to ask each group to share one thing they have discovered about the calculator. (For example, what does the ^ key do? How do I change a number to a fraction?) My group discovered: Other groups discovered: 3) Exponents ??? =? From the first problem we learned that we can use the button to square a number. So you can type in But now, back to QUESTION 1. Let’s figure out why we did not get the correct answer when we attempted to square negative three. When we square a negative number, it is going to be necessary to put that negative number in parenthesis. When you simply enter – 3 into the calculator, it thinks you are asking it to perform – (3 ), which is why you get -9. To square negative numbers we must:________________ 3 In class work MATH-013 Graphing Calculator Intro 4) Let’s construct a scatter plot for these scores. A. Enter the data into lists by pushing: STAT, ENTER (If your list has data in it, you can clear the data by arrowing up so L1 is shaded, then push CLEAR, and arrow back down. Your list should be empty now.) B. Type the numbers for the 1st test into L1 and the numbers for the 2nd test into L2. C. Push Y=, the button at the top left of your calculator screen, and clear any equations. D. Turn your plot on by arrowing up to PLOT1 and pushing ENTER. (It should be shaded if it is on.) E. To see the graph or scatterplot, push ZOOM, 9. Sketch the scatterplot. Is there any pattern in this data? Scientific Notation in the graphing calculator. Sometimes the calculator will show an answer like 5.36275E6. This is a way of showing scientific notation. 5.36275E6 means 5.36275 × 10 To write the scientific notation in standard form, you multiply the numbers. This moves the decimal to the right 6 places; you must fill in the extra place(s) with a 0(s). So, 5.36275?6 equals 5,362,750. If the E number is negative, move the decimal to the left, filling in 0’s for any blank place values. 4.576 E-5 means 4.576 × 10 which equals 0.00004576 4 In class work MATH-013 Graphing Calculator Intro 5) 2 6) 4 Now you try these 7) 3 Don’t use the E notation! 8) 2 Don’t use the E notation! 9) (3 − 3 ∙ 4) ÷ 121 − 16 Write this answer as both a decimal rounded to tenths and a fraction. 10) − + + +<- if you don’t know how to find a square root, ask! 11) the city of newark uses salt to melt snow on the streets. the salt solution the city uses will freeze at −21℃. use the formula below, and your if="" you="" don’t="" know="" how="" to="" find="" a="" square="" root,="" ask!="" 11)="" the="" city="" of="" newark="" uses="" salt="" to="" melt="" snow="" on="" the="" streets.="" the="" salt="" solution="" the="" city="" uses="" will="" freeze="" at="" −21℃.="" use="" the="" formula="" below,="" and="">