C1 Quiz

• Descriptive is to inferential as summarizing is to accounting for chance
• The branch of statistical practice concerned with "chance" is known as inferential statistics.
• Professor Ng observes a 3-point average difference in coordination scores between the trained and untrained groups. In order to rule out sampling variation as a possible explanation, she will make use of inferential statistics.
• The idea of a random sample is particularly important for statistical inference.
• Characteristic is closest in meaning to the word "variable" as used in statistics.
• Distance traveled is a variable that represents a ratio scale.
• SAT scores is a variable that represents, at best, an interval scale.
• Is there a difference in speed of learning under Method A and Method B? is a purely substantive question.
• A researcher wants to know if there are differences in height among males and females. This is a purely substantive question.
• A researcher wants to find out how many people prefer brand X over brand Y. This is a purely substantive question.
• A researcher wants to determine whether or not there is a significant relationship between age and income. This is a purely substantive question.
• Descriptive questions involve describing characteristics of data or variables.
• Inferential questions involve making statements about populations based on samples.
• The purpose of statistical analysis is to determine whether or not two variables are related. This is a purely substantive question.
• Purely substantive questions do not involve inferring anything from data; they simply describe what has been observed.
• In the ordinary course of investigation, statistical matters intervene between substantive question and substantive conclusion.
• Arm lengths are scores for which variables would necessarily be approximate numbers.
• Variables can be classified as categorical (nominal) or numerical (quantitative).
• What is your annual income? is a question does not reflect an ordinal scale.
• "Letter grade in a statistics course" would be considered a ratio variable,
• Sampling variation  is closest in meaning to the word "variable" as used in statistics.
• A ratio scale is the most informative scale as it tends to tell about the order and number of the object between the values of the scale. The most common examples of this scale are height, money, age, weight etc.
• The nominal scale is the least informative scale because it only tells us that two objects belong to different categories but not how much difference there is between them.
• An interval scale is similar to a ratio scale except that zero on the scale has no real meaning. For example, temperature measured by Fahrenheit is an interval scale since zero degrees Fahrenheit doesn't mean that something isn't hot at all; rather, it means that something is very cold.
• The difference between interval vs ratio scale comes from their ability to dip below zero. Interval scales hold no true zero and can represent values below zero. For example, you can measure temperatures below 0 degrees Celsius, such as -10 degrees. Ratio variables, on the other hand, never fall below zero.
• "Letter grade in a statistics course" would be considered a quantitative variable.
• Distance traveled is a  variable representing a ratio scale.
• SAT score is a variable that represents, at best, an interval scale.
• Descriptive is to inferential as summarizing is to accounting for chance.
• Professor Ng observes a 3-point average difference in coordination scores between the trained and untrained groups. In order to rule out sampling variation as a possible explanation, she will make use of inferential statistics.
• "Letter grade in a statistics course" would be considered "Letter grade in a statistics course" would be considered a quantitative variable.
• Distance traveled is a variable which represents a ratio scale.
• An SAT score is a variable which represents, at best, an interval scale.
• A substantive question is necessarily one that is about a particular subject matter, such as perception or reaction time.
• Is there a difference in speed of learning under Method A and Method B? is an example of a purely substantive question.
• If measurement is to the nearest 10 pounds, then a score of 540 pounds means 535.0-545.0 pounds.
• The difference between interval vs ratio scale comes from their ability to dip below zero. Interval scales hold no true zero and can represent values below zero. For example, you can measure temperatures below 0 degrees Celsius, such as -10 degrees. Ratio variables, on the other hand, never fall below zero.