Intro to Statistics Module 3 (A+ Graded 100% Verified)

Intro to Statistics Module 3 (A+ Graded 100% Verified) Mean Correct Ans: Measure of center found by adding the values and dividing the total by the number of values Median Correct Ans: Measure of center that is the middle value when the original data values are arranged in order of increasing (or decreasing) magnitude. Mode Correct Ans: Value that occurs most frequently (May be bimodal, multimodal, or have no mode) Midrange Correct Ans: Value midway between the max and min values in the original data set. = max+min / 2 Positively skewed Correct Ans: Skewed to the right (Starts high on the left and goes to zero on the right) Negatively skewed Correct Ans: Skewed to the left (Starts at zero on the left and raises to its max on the right) Range Correct Ans: = Max value - Min value Standard deviation of a sample Correct Ans: Measure of variation of values about the mean Sample standard deviation equation Correct Ans: = Square root of: sum of values times(x - mean of all values of x)squared / n(number of values in the sample) =sigma (x-barx) squared Shortcut formula for sample standard deviation Correct Ans: = Square root of: n times sum of all values squared - (sum of all values times x) squared / n-1 =n sigma xsquared - (sigma x) squared / n-1 Mean = Sum of all values of x Correct Ans: = Sigma / n = sum of all values / number of values Standard deviation of a population Correct Ans: = square root of: (sum of all values times (x-mean)squared) / n Sample variance (s2) = Population variance (o2) = Correct Ans: Sample - Square of the sample standard deviation Population - Square of the population standard deviation Usual value Correct Ans: = Usual value + or - 2(deviation) Empirical rule Correct Ans: - 68% fall within 1 standard deviation - 95% fall within 2 standard deviations - 99.7% fall within 3 standard deviations Chebyshev's theorem Correct Ans: Any set of data lying within K standard deviations of the mean is always at least 1-1/ksquared, where k is any positive number greater than 1 k=2: at least 75% of all values lie within 2 standard deviations of the mean k=3: at least 89% of all values lie within 3 standard deviations of the mean Empirical rule equation Correct Ans: xbar - s x & x +/-s = 68% x +/-2s = 95% x +/-3s = 99.7% z score (or standardized value) Correct Ans: Sample: z = x-xbar / s(variation) Population: z = x-u/ o(variation) Quartiles Correct Ans: Q1 = 25% Q2 = 50% Q3 = 75% Percentiles Correct Ans: Divide the sorted data into 100 equal parts. For example, at least 45% of the sorted values are less than p45 Percentile equation Correct Ans: Number of values less than x / total number of values times 100 Notation Correct Ans: n = total number of values in the data set k = percentile being used L = locator that give the position of a value (i.e. the 10th value) Pk = kth percentile Location of x Correct Ans: L = k/100 times n Converting from kth percentile to corresponding data value 1. Sort the data (lowest to highest) 2. Compute - (k/100)n 3. Is "L" a whole nummber? If yes, percentile is between value of "L" and next value. If no, change "L" by rounding it up to the next larger whole number 4. The value of pk is the "Lth" value, counting from the lowest Correct Ans: ...