类别 全部 - graphs - probability - sampling - prediction

作者:Gursewak Gill 4 年以前

338

Relation, Analyzing Linear Relations, and Modelling With Graphs

Relation, Analyzing Linear Relations, 
and Modelling With Graphs

The slope of a line is the steepness of the line. The slope is calculated using the formula rise/run or rise over run. The other formula to calculate the slope is y2-y1/x2-x1

Slope

Partial variation lines have an equation of y=mx+b because they go trough b which is also known as the y intercept.

Direct variation occurs when the dependent variable changes by the same factor as the independent variable. Direct variation lines formula is y=mx.

Direct and Partial variation

Y and X represent the points that make the line. M represents the slope of the line and b represents the y intercept of the line Horizontal lines have a formula of y=b Vertical lines have a formula of x=a

y=mx+b

The x-intercept is the x-coordinate of the point when the line crosses the x-axis. The y-intercept is the y-coordinate of the point when the line crosses the y-axis.

Graphing a line using Intercepts

The Rule of Four can be used to show a relation in four ways: words, a diagram or graph, numbers, and equation.

The rule of Four

A distance-time- shows how distance varies with time. A rising line – increases as time increases. A falling line – decrease in distance with time. A horizontal line – distance remains constant as time passes

Distance Time Graphs

Standard form is y=mx+b. You can change an equation in standard form to slope y-intercept form by rearranging the equation.

The standard form is Ax + By + C = 0 where A, B and C are integers, A and B are not both zero, A must be › 0 (If the coefficient of the x-term is negative, you can multiply both sides by (-1) to express the equation in standard form)

Standard Form and Intercept form

A hypothesis is an educated guess. There are two sources of data. A primary source and a secondary source

Hypothesis' and Sources of Data

Rate of change is change in one quantity relative to the change in another.

Rate of Change

In a linear relationship the points form a straight line have a formula of y=mx or y=mx+b. In a nonlinear relationship the points make a curved line and have a formula with an exponent in it Eg. y=mx^2+b.A difference table, is a table of values with 1 extra column. To find first differences, subtract consecutive values of y (dependent variable).

First Differences

When the prediction involves a point within the range of the values of the variable represented on the x-axis, this is called interpolating. When the prediction involves a point outside the range of the values of the variable represented on the x-axis, this is called extrapolating.

When making a scatter plot graph you would use a line of best fit to show the data. The line of best fit is made with around the same number of points on the top and on the bottom of the line to make it equal (A line of best fit is used for making predictions).

Points in a scatter plot often show a pattern or a trend. An outlier is a point that does not follow the trend.

A scatter plot is a graph that shows the relationship between two sets of numeric data or variables. When graphing two sets of data, the independent variable is graphed along the x-axis and the dependent variable is graphed along the y-axis.

Analyzing Data

In statistics, sampling bias is a bias in which a sample is collected in such a way that some members of the intended population have a lower or higher sampling probability than others.

Non-random sampling is any sampling method in which the process that determines whether a member of the population is selected for inclusion in the sample is guided by a non-chance or non-random process.

A stratified sample is one that ensures that subgroups (strata) of a given population are each adequately shown in the whole sample population of a research study. For example, one might divide a sample of adults into subgroups by age, like 18–28, 10–29, 30-39–49, 40–58, and 67 and above.

Systematic sampling a of probability sampling method where sample members from a larger population are selected according to a random starting point but with a fixed, periodic interval. This interval, called the sampling interval, is calculated by dividing the population size by the desired sample size.

Simple random sampling is the basic sampling technique where we select a group of subjects (a sample) for study from a larger group (a population). Each individual is chosen entirely by chance and each member of the population has an equal chance of being included in the sample.

Bias

Non-Random Sampling

Stratified Random Sampling

Systemic Random Sampling

Simple random sample

There are 5 different types of sampling

Sampling Principles

The solution of a linear system o 2 equations is the point where the graphs intercept.

A linear system is two or more linear equations together. In given equation, an ordered pair satisfies the equations when the left side of the equation equals the right side, when x and y are subsided into equations.

Linear Systems

Relation, Analyzing Linear Relations, and Modelling With Graphs