In a sample of 110 trees in a wood lot, 15 Oak, 27 Maple, 19 Pine, 22 Spruce and 27 Birch were observed. To test that tree species are uniformly distributed in the wood lot, a forester uses the chi-square test. He calculates that the expected number of Pine in the wood lot should be:
Answers
Step-by-step explanation:
Data Samples
There are three types of data samples valid in this package:
1)
A data sample that follows a specific distribution
Data samples can easily be created using random variables with corresponding distributions. For example, to create a Normal random variable, one would call NormalRandomVariable(μ,σ). For more information, see the Random Variable overview page.
2)
A data sample stored in a list or a Vector
Each element in a list or Vector data sample represents a single recorded observation. There is no difference between a list sample and a Vector sample, either is valid.
3)
A data sample stored in a Matrix
A Matrix data sample is treated as a collection of several list or Vector samples. Each column of the Matrix represents an individual sample.
Work with Data Samples
1)
Compute quantities of data samples
There are many commands for computing quantities of data samples. This includes many different quantities, such as the Mean Value, the Standard Deviation, the Skewness, and many more. Also in this package, users are not only able to query for a symbolic formula or exact numeric value for a given quantity from a data sample, but it is also possible to return a visualization of the result.
2)
Explore distributions
Users can easily explore the important properties of a distribution by using the command, ExploreRV. ExploreRV takes an arbitrary statistical distribution and displays an interactive interface to explore its various parameters. This includes returning key quantities, such as the mean, median and more, as well as returning visualizations of the CDF and PDF.
3)
Apply hypothesis tests
To test a given hypothesis, there are several hypothesis tests available, including OneSampleTTest, ChiSquareGoodnessOfFitTest, ShapiroWilkWTest, and more. To better explain how and when to use different hypothesis tests, a new command, TestsGuide, is introduced in this package to direct a student through the process of choosing an appropriate test. You can read more on the Hypothesis Tests Overview page.