Descriptive Statistics Quiz

<p>25 (C)</p> Signup and view all the answers

<p>√(Σ(𝑥𝑖 − 𝑥̄)^2 / (n-1)) (A)</p> Signup and view all the answers

<p>4 (A)</p> Signup and view all the answers

<p>x(1), x(2), x(3), x(4) (D)</p> Signup and view all the answers

<p>Σ(xi) / n (B)</p> Signup and view all the answers

<p>4.25 (B)</p> Signup and view all the answers

<p>Outliers (D)</p> Signup and view all the answers

<p>Time series data (D)</p> Signup and view all the answers

<p>Σ(xi) / N (C)</p> Signup and view all the answers

<p>Mean (D)</p> Signup and view all the answers

<p>4 (D)</p> Signup and view all the answers

<p>3 (B)</p> Signup and view all the answers

<p>The median is less affected by extreme values. (C)</p> Signup and view all the answers

<p>The mean is greater than the median. (D)</p> Signup and view all the answers

<p>Interquartile range (C)</p> Signup and view all the answers

<p>The data is perfectly symmetrical. (D)</p> Signup and view all the answers

<p>Range (A)</p> Signup and view all the answers

<p>The difference between the largest and smallest data values. (C)</p> Signup and view all the answers

<p>Mean (D)</p> Signup and view all the answers

<p>$\frac{\sum_{i=1}^{n} (x_i - \mu)^2}{n}$ (B)</p> Signup and view all the answers

<p>The standard deviation is the square root of the variance. (B)</p> Signup and view all the answers

<p>The data is clustered closely together. (B)</p> Signup and view all the answers

<p>The interquartile range is not affected by outliers. (A)</p> Signup and view all the answers

<p>Standard deviation is measured in the same units as the original data. (C), Standard deviation is always a positive value. (D)</p> Signup and view all the answers

<p>Evaluating the performance of a stock portfolio, where a higher variation in returns is generally seen as positive. (D)</p> Signup and view all the answers

<p>150, 161, 168, 177.5, 205 (A)</p> Signup and view all the answers

<p>The distribution is skewed right. (A)</p> Signup and view all the answers

<p>84.00 (C)</p> Signup and view all the answers

<p>Shifting (D)</p> Signup and view all the answers

<p>Scaling (D)</p> Signup and view all the answers

<p>Scaling and Shifting (D)</p> Signup and view all the answers

<p>Both the mean and standard deviation are affected. (A)</p> Signup and view all the answers

<p>16.5 cm (A)</p> Signup and view all the answers

<p>50% (C)</p> Signup and view all the answers

<p>Calculate the mean and standard deviation (D)</p> Signup and view all the answers

<p>136.25 cm (A), 202.65 cm (D)</p> Signup and view all the answers

<p>Obtain a five-number summary, Calculate the IQR and limits, Draw a horizontal number line, Draw vertical lines for quartiles and box, Identify outliers, Draw lines for outlier data points (C)</p> Signup and view all the answers

<p>Resistant to extreme values (B)</p> Signup and view all the answers

<p>To identify potential errors or unusual observations (B)</p> Signup and view all the answers

<p>An outlier is a data point that is significantly different from other data points. It can be caused by typos, experimental error, or random chance. (A)</p> Signup and view all the answers

The difference between the largest and smallest value in data.

Average of the squared distances of data values from the mean.

The square root of variance, shows data spread around the mean.

Measure of dispersion, difference between the 75th and 25th percentiles.

Variance calculated using the entire population of data.

Variance calculated from a sample of the population.

The squared difference between each data point and the mean.

The average of a set of data values, sum divided by count.

The folder where R looks for data files.

Use the command read.table() to load CSV data in R.

A graphical representation of data distribution.

Data collected over time to analyze trends.

Three key characteristics: shape, center, spread.

Key statistics: mean, median, mode that describe typical data values.

Mean calculated from sample data, denoted as x̄.

Mean calculated from an entire population, denoted as μ.

Calculated as s² = Σ(xi - x̄)² / (n-1), where x̄ is the sample mean.

Calculated as σ = √(Σ(xi - μ)² / N), where μ is the population mean.

Arrange data and pick the middle value. Example: 4, 2, 7, 1, 8 gives median 4.

Arrange data and average the two middle values. Example: 4, 2, 7, 1, 8, 8 gives median 5.5.

The most frequently occurring value in a data set.

Identify the value(s) that appear most often. Can have no mode or multiple modes.

Mean is affected by extreme values, while median is more robust and stable.

In skewed distributions, the mean and median differ; mean provides less accurate center measure.

Median is a more reliable measure of central tendency compared to the mean in skewed data.

A graphical representation of data distribution using five-number summary.

Consists of minimum, Q1, median, Q3, and maximum values in a dataset.

Values that divide data into four equal parts: Q1, Q2 (median), Q3.

Distribution with a longer tail on the left side than the right.

Distribution with a longer tail on the right side than the left.

A method of altering data using a formula to adjust values.

Includes minimum, maximum, quartiles, and median in a visual format.

The middle value of a dataset, separates higher and lower halves.

The range of the middle 50% of a dataset, calculated as Q3 - Q1.

Q1 is the first quartile (25th percentile) and Q3 is the third quartile (75th percentile) in a dataset.

Extreme values in data that differ significantly from others, potentially errors or random chance.

Determine outliers using IQR: lower limit (LL) = Q1 - 1.5IQR; upper limit (UL) = Q3 + 1.5IQR.

IQR = Q3 - Q1 measures variability in the middle half of data.

Graphical display summarizing data using the five-number summary, including outliers.