HBX Core Business Analytics - Full Study Guide Solutions

HBX Core Business Analytics - Full Study Guide Solutions Skewness - ANSWER-Skewness measures the degree of a graph's asymmetry. If the right tail is longer, we say the distribution is skewed to the right or "right-tailed." Likewise, if the left tail is longer, we say the distribution is skewed to the left or "left-tailed." Rules of thumb for the normal distribution - ANSWER-About 68% of the probability is contained in the range reaching one standard deviation away from the mean on either side: P(μ−σ≤x≤μ+σ)≈68% About 95% of the probability is contained in the range reaching two standard deviations (1.96 to be exact) away from the mean on either side: P(μ−2σ≤x≤μ+2σ)≈95% We'll use two standard deviations when discussing the normal distribution conceptually, but we will always use 1.96 for actual calculations in Excel. ©EMILLECT 2024/2025 ACADEMIC YEAR. ALL RIGHTS RESERVED FIRST PUBLISH OCTOBER 2024 Page 2/11 About 99.7% of the probability is contained in the range reaching three standard deviations away from the mean on either side: P(μ−3σ≤x≤μ+3σ)≈99.7% Bias - ANSWER-avoid biased results by - phrasing questions neutrally -ensuring that the sampling method is appropriate for the demographic of the target population -pursuing a high response rate Normal Distribution - ANSWER-a unique symmetrical shape whose centre and width are determined by its mean and standard deviation respectively. z-value - ANSWER-the distance that x lies from the mean, measured in standard deviations. Central Limit Theorem - ANSWER-If we take enough sufficiently large samples from any population, the means of those samples will be normally distributed regardless of the shape of the underlying population. Confidence interval - ANSWER-An estimate of the range in which the true population mean likely lies. ©EMILLECT 2024/2025 ACADEMIC YEAR. ALL RIGHTS RESERVED FIRST PUBLISH OCTOBER 2024 Page 3/11 Outlier - ANSWER-Technically, a data point is considered an outlier if it is more than a specified distance below the lower quartile or above the upper quartile of a data set. Let's start with a couple of definitions. The lower quartile, Q1, is the 25th percentile—by definition, 25% of all observations fall below Q1. The upper quartile, Q3, is the 75th percentile—75% of all observations fall below Q3. The interquartile range (IQR) is the difference between the upper and lower quartiles, that is, IQR=Q3-Q1. Histogram - ANSWER-Histogram, also called a bar chart. A histogram's x-axis represents bins corresponding to ranges of data; its y-axis indicates the frequency of observations falling into each bin. Descriptive Statistic - ANSWER-Provide a quick overview of a data set without showing every data point. Central Tendency - ANSWER-"central tendency" of a data set—an indication of where the "center" of the data set lies. Mean - ANSWER-Mean (average): The mean is equal to the sum of all of the data points in a set, divided by n, the number of data points. Median - ANSWER-Median: The middle value of a data set. The same number of data points fall above and below the median. Mode - ANSWER-Mode: The value that occurs most frequently in a data set