average and spread Flashcards","topicId":"cfc916ae-3785-4c0e-9eb6-5111850e88da","topicSlug":"measures-of-average-and-spread","cards":[{"id":"fa32fc7c-f863-419f-8730-2c9db785ebf7","cardType":"basic","front":"The ordered data are 4, 6, 7, 9, 11, 15. What is the median?","back":"8","points":1,"mcqOptions":null},{"id":"0fe80d73-ff56-44c5-812a-b8cf1934f300","cardType":"basic","front":"The values 3, 5, 5, 7, 8 have which mode?","back":"5","points":1,"mcqOptions":null},{"id":"e1e6cc07-5478-4d1d-982b-0e3f8e0e245b","cardType":"basic","front":"What is the range of 12, 15, 18, 18, 22?","back":"10","points":1,"mcqOptions":null},{"id":"f59b5616-fe5c-454e-9d3a-79703fab7978","cardType":"basic","front":"If $Q_1=42$ and $Q_3=68$, what is the IQR?","back":"26","points":1,"mcqOptions":null},{"id":"1eadaf03-8031-4d5e-9ead-01bf5c839f47","cardType":"cloze","front":"For $n$ observations, the arithmetic mean is $\\text{[...]}$.","back":"For $n$ observations, the arithmetic mean is $\\boxed{\\bar{x}=\\frac{\\sum x_i}{n}}$.","points":null,"mcqOptions":null},{"id":"217f674c-5054-4ddb-96e9-e04869abd541","cardType":"basic","front":"A value $x_i$ occurs $f_i$ times. What does $f_ix_i$ represent?","back":"Its contribution to the total of all observations.","points":1,"mcqOptions":null},{"id":"2effcb1b-7da2-4ceb-9100-d6d3a5662de4","cardType":"cloze","front":"For frequency data, the mean is $\\text{[...]}$.","back":"For frequency data, the mean is $\\boxed{\\bar{x}=\\frac{\\sum f_ix_i}{\\sum f_i}}$.","points":null,"mcqOptions":null},{"id":"a431d5a0-f2de-470b-9577-bb77a9d61305","cardType":"basic","front":"Which class is the modal class in grouped data?","back":"The class with the greatest frequency.","points":1,"mcqOptions":null},{"id":"8f13a820-92ff-4d32-bf6d-9039120fc7fc","cardType":"basic","front":"Why must data be ordered before finding the median?","back":"The median depends on the middle position.","points":2,"mcqOptions":null},{"id":"d4a6d32b-b4e6-4f8b-b602-7828b1c5580a","cardType":"basic","front":"Why is a grouped-data mean only an estimate?","back":"Class midpoints replace unknown exact values.","points":2,"mcqOptions":null},{"id":"47eb5d8d-5896-4352-a23c-41ec72698fa2","cardType":"basic","front":"In a data set of 80 observations, at which cumulative frequency is $Q_3$ located?","back":"60","points":1,"mcqOptions":null},{"id":"e558bbb6-f39d-4d3b-a1b8-8aa69fa04975","cardType":"cloze","front":"The interquartile range is $\\text{[...]}$.","back":"The interquartile range is $\\boxed{\\operatorname{IQR}=Q_3-Q_1}$.","points":null,"mcqOptions":null},{"id":"4973e944-582d-49b0-9074-5a22add84762","cardType":"basic","front":"What does a smaller IQR indicate about the middle 50% of values?","back":"They are less variable and more consistent.","points":2,"mcqOptions":null},{"id":"76faf1dd-8f55-4cfb-8d01-b96466a63362","cardType":"basic","front":"Why is the median less affected by an extreme outlier than the mean?","back":"It depends on position, not the outlier's magnitude.","points":2,"mcqOptions":null},{"id":"f5a4b20c-8d63-4ea5-b1f3-3c517600bfc8","cardType":"basic","front":"Why are deviations from the mean squared when calculating variance?","back":"To prevent positive and negative deviations cancelling.","points":2,"mcqOptions":null},{"id":"563e3a8f-e5d3-4795-9dc8-006633e2a9d4","cardType":"cloze","front":"The efficient variance formula for raw data is $\\text{[...]}$.","back":"The efficient variance formula for raw data is $\\boxed{\\operatorname{Var}(X)=\\frac{\\sum x_i^2}{n}-\\bar{x}^{\\,2}}$.","points":null,"mcqOptions":null},{"id":"170c8f6c-521e-42ca-9759-54789cd7b1ef","cardType":"cloze","front":"For frequency data, variance is $\\text{[...]}$.","back":"For frequency data, variance is $\\boxed{\\operatorname{Var}(X)=\\frac{\\sum f_ix_i^2}{\\sum f_i}-\\bar{x}^{\\,2}}$.","points":null,"mcqOptions":null},{"id":"4aec75c2-d5f8-4567-84d3-384eb76349f0","cardT

2.2.6 Measures of average and spread Flashcards

2.2.6 Measures of average and spread Flashcards