Statistics Midterm 1 Flashcards

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Questions and Answers

What is the difference between a class boundary and a class limit?

Class limits are possible data values, while class boundaries are values halfway between the upper class limit of one class and the lower class limit of the next.

How do you find the class width?

Largest data value - smallest data value / desired number of classes.

What is the midpoint in a data set?

Lower class limit + upper class limit / 2.

What does frequency measure?

How often a number occurs within the class limits. Signup and view all the answers

What is relative frequency?

The fraction of times an answer occurs. Signup and view all the answers

What is cumulative relative frequency?

The accumulation of the previous relative frequencies. Signup and view all the answers

What are basic distribution shapes?

Not specified. Signup and view all the answers

What is a stem and leaf display?

A method of exploratory data analysis used to rank-order and arrange data into groups. Signup and view all the answers

What is the mean of a distribution?

The arithmetic average obtained by adding the scores and dividing by the number of scores. Signup and view all the answers

What is the median in a distribution?

The middle score in a distribution, with half the scores above it and half below it. Signup and view all the answers

What is the mode?

The value that occurs most frequently in a given data set. Signup and view all the answers

What does range measure?

The difference between the highest and lowest scores in a distribution. Signup and view all the answers

What are the steps for calculating population variance?

<ol> <li>Calculate the mean (μ). 2. Subtract the mean from each data point to find deviations. 3. Square each deviation. 4. Add the squared deviations. 5. Divide by the number of data points (N).</li> </ol> Signup and view all the answers

What does Σx represent?

Add numbers. Signup and view all the answers

What does Σx^2 represent?

Add the products of each number squared. Signup and view all the answers

What is standard deviation s?

E = Sum; Xi; u = mean; N = size of population. Signup and view all the answers

What is sample variance s^2?

Not specified. Signup and view all the answers

What is the coefficient of variation?

A measure of relative variability computed by dividing the standard deviation (s) by the mean (x) and multiplying by 100. Signup and view all the answers

What is the slope m?

r times Sy/Sx. Signup and view all the answers

Study Notes

Class Boundaries vs Class Limits

Class limits represent possible data values within a class.
Class boundaries are values located halfway between the upper limit of one class and the lower limit of the next class.

Class Width

Calculated by subtracting the smallest data value from the largest and dividing by the desired number of classes.

Midpoint

Determined by averaging the lower and upper class limits of a class.

Frequency

Represents how often a specific number occurs within defined class limits.

Relative Frequency

The proportion of times an answer appears, calculated by dividing each frequency by the total sample size.

Cumulative Relative Frequency

A running total of relative frequencies, found by adding the current relative frequency to the sum of previous relative frequencies.

Basic Distribution Shapes

Understanding the general forms distributions can take.

Stem and Leaf Display

A data visualization technique for rank-ordering and grouping data effectively.

Mean

The arithmetic average of a dataset, found by summing all scores and dividing by the total number of scores.

Median

The central score in a data distribution, with equal numbers of scores above and below it.

Mode

The value that appears most frequently in a dataset.

Range

The difference between the highest and lowest scores within a dataset.

Population N

Steps to calculate variance and standard deviation:
- Compute the mean (μ).
- Determine the deviations from the mean for each data point.
- Square each deviation.
- Sum the squared deviations.
- Divide by the total number of data points to get variance.
- Take the square root of the variance for standard deviation.

Verify Σx

Involves summing a set of numbers.

Verify Σx²

Requires adding the squares of each number in a dataset.

Standard Deviation (s)

Formula involves summing deviations and adjusting for population size.

Sample Variance (s²)

Measure of variability calculated from sample data.

Coefficient of Variation

Indicates relative variability by dividing the standard deviation by the mean and multiplying by 100.

Slope (m)

Calculated with the formula: ( r \times \frac{S_y}{S_x} ), where ( r ) is the correlation coefficient, ( S_y ) is the standard deviation of y, and ( S_x ) is the standard deviation of x.

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Description

Test your knowledge on key concepts from Statistics Midterm 1 with these flashcards. This quiz covers definitions and differences between class boundaries and limits as well as calculations involving class width. Perfect for quick review before the exam!