Ch 1: Intro to Statistics Statistics Notes Individual Self-PracticelStudy in Groups: Identify the individuals, population, sample, variables (and whether they are discrete, continuous or qualitative) and the data corresponding to each variable in this study ofworld conditions. Country Population # of Cell Phones Average Age Of Drives on Billionaires Australia 8,544,586 244,490,000 64 left China 1,376,048,940 986,253,000 49 right Mexico 127,017,224 94,965,305 62 right US 321,773,631 331,600,000 65 right Individuals? Population? Sample? Variables? Data? Levels of Measurement Def Nominal Level of Measurement - Data that consists of , , or only. However, data cannot be arranged in an ordering scheme or hierarchy. EX: Def Ordinal Level of Measurement - Categorical data that can be arranged in some but differences cannot be determined or are meaningless. EX: Def Interval Level of Measurement - Numerical data in which the difference between any two data values is . However, there is no natural zero starting point and ratios are meaningless. EX: Def Ratio Level of Measurement Numerical data with a natural zero starting point and ratios are meaningful. Zero indicates that none ofthe quantity is present. EX: Q: Determine the level ofmeasurement of each variable. a) Nation of origin b) Movie ratings of one star through five stars c) Volume of water used by a household in a day cl) Year of birth of college students e) Highest degree conferred (high school, bachelor's, f) Eye Color and so on) Ch 1: Intro to Statistics Statistics Notes Population Parameters and Sample Statistics Recognizing Parameters v. Statistics When given a number (parameter or statistic), does it sound Population Parameters like it came from the whole group or just a part? LL Def A parameter is a. Population Population Population Population Proportion Mean Standard describing some characteristic of a Number Variance (percentage) (average) Deviation is based on the entire population. Sample Statistics Def A statistic is a describing some characteristic of a Number Sample Sample Sample Sample based on the sample. Proportion Mean Standard Variance (percentage) (average) Deviation Example 3: Is the underlined value a parameter or statistic? A) Twelve men have walked on the moon. The average time these men spent on the moon was 43.92 hours. B) Interviews of 100 adults, conducted nationwide, found that 44% could state the minimum age required for the office of President. C) The average score for a class of 28 students taking a calculus midterm was 72%. D) In a national survey, 9.6% of respondents aged 12 to 17 reported using illicit drugs within the past month. Different Variables QUALITATIVE QUANTITATIVE -Data consists of - Data consists of OR representing c or measurements. DISCRETE CONTINUOUS - has a many number of values possible values Example 4: Are the following variables quantitative or qualitative? Which are discrete or continuous (keep in mind, they may be neither)? A) Hair Color B) Number C) High Temperature D) * Jersey Number 2Ch 1: Intro to Statistics Statistics Notes Section 1.1 Introductions to the Practice of Statistics The SITUATION I The PROBLEM The (IMPERFECT) SOLUTION We want to know SOMETHING Most of the time the GROUP we're Don't ask EVERYONE about WHAT YOU'RE about a CERTAIN GROUP interested in is . INTERESTED IN, just ask and infer. Ex: Of UCLA undergraduate Ex: As of 2017, UCLA had about Ex: Ask UCLA undergraduates if students, what proportion likes they like poke bowls and use the collected poke bowls? undergraduates. to infer about the total proportion of undergraduates who like poke bowls. By the end of this lesson, you will be able to... 1. describe what "statistics" means in the context ofthis course. 2. explain the process of statistics 3. distinguish between qualitative and quantitative variables 4. distinguish between discrete and continuous variables 5. determine the level of measurement of a variable Def Statistics: Def Data are of observations. POPULATION: the group to be studied. SAMPLE: a . ' population that is being studied. Example 1: A recent survey by The New York Times found that 63% of voters surveyed in New York, New Jersey, and Connecticut say that the restrictions put in place in their state to slow the spread of the coronavirus are about right. From April 30th through May 4th, 2020, self-identied registered voters in New York, New Jersey and Connecticut were interviewed via telephone. In total, 915 voters in New York, 943 voters in New Jersey and 1,045 voters in Connecticut responded. The respondents were selected via Random Digit Dial sampling through both landline phones and mobile phones. In this example, what is our population and what is the sample? Population: Sample: Data: Note: We won't stop at the sample statistic. It is used to estimate the population parameter! Example 2: We want to know about parking for students the rst week of school at Rio. We survey 100 Rio Hondo students who drank coffee in the morning. 65 % said they did. Population? Population Parameter? Sample? Sample Statistic