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Solving predictions and probability problems. Distinguishing between dependent and independent events. Interpreting charts and histograms. Our resources can be used online and offline, on virtually any computer or mobile device. Browse around our website and start playing! Find Math games to practice every skill.
A time series graph is a line graph that shows data such as measurements, sales or frequencies over a given time period. They can be used to show a pattern or trend in the data and are useful for making predictions about the future such as weather forecasting or financial growth.
Time Series Modelling 1. Plot the time series. Look for trends, seasonal components, step changes, outliers. 2. Transform data so that residuals are stationary. (a) Estimate and subtract Tt,St. (b) Differencing. (c) Nonlinear transformations (log, √ ·). 3. Fit model to residuals. 42
The relative frequency is equal to the frequency for an observed value of the data divided by the total number of data values in the sample. (Remember, frequency is defined as the number of times an answer occurs.) If: f = frequency. n = total number of data values (or the sum of the individual frequencies), and. RF = relative frequency, then:
log(100) This usually means that the base is really 10. It is called a "common logarithm". Engineers love to use it. On a calculator it is the "log" button. It is how many times we need to use 10 in a multiplication, to get our desired number.
We use log as an abbreviation for the word logarithm. To find the value of a logarithm we need to solve an exponential equation. Example (a) The solution of 2x = 8 is x = 3. We can write this in logarithm notation as log 2 8 = 3 ‘log of 8 to base 2 is 3’ (b) x = 5 is the solution of 2x = 32. We can write this using logarithms as log 2
The goal of statistics is not to perform numerous calculations using the formulas, but to gain an understanding of your data. The calculations can be done using a calculator or a computer. The understanding must come from you.
