/*! This file is auto-generated */ .wp-block-button__link{color:#fff;background-color:#32373c;border-radius:9999px;box-shadow:none;text-decoration:none;padding:calc(.667em + 2px) calc(1.333em + 2px);font-size:1.125em}.wp-block-file__button{background:#32373c;color:#fff;text-decoration:none} Problem 8 Use a computer program to comput... [FREE SOLUTION] | 91Ó°ÊÓ

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Use a computer program to compute the lower 10 th percentile of a \(t\) distribution with 54 df.

Short Answer

Expert verified
The lower 10th percentile of a t-distribution with 54 degrees of freedom is approximately -1.3027.

Step by step solution

01

Understand the Problem

To solve this exercise, we need to determine the value at the lower 10th percentile for a t-distribution with 54 degrees of freedom. This means we need to find a t-value where 10% of the data lies below this point in the distribution.
02

Set Up the Program

We need to select a programming tool or environment that handles statistical distributions, such as Python with SciPy or R with its built-in functions. Ensure the required software is installed and ready to execute commands.
03

Use a Statistical Function

For a tool like Python, use the SciPy library which offers a built-in function for percentile calculation of t-distributions. In Python, this is `scipy.stats.t.ppf`. For R, use `qt` function which serves a similar purpose.
04

Input Parameters

Input the degrees of freedom (54) and the desired percentile (0.10 for the 10th percentile) into the function. For example, in Python, execute `scipy.stats.t.ppf(0.10, 54)`. In R, the command is `qt(0.10, 54)`.
05

Execute and Collect Results

Run the program with the input parameters to calculate and collect the result, which is the t-value corresponding to the lower 10th percentile of the distribution.

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Key Concepts

These are the key concepts you need to understand to accurately answer the question.

Percentile Calculation
Calculating percentiles is a valuable skill in statistics. It helps us understand where a particular value lies in a distribution. A percentile indicates the relative standing of a value in a dataset. For instance, the 10th percentile marks a point below which 10% of the data falls. To find this in a t-distribution, we use specialized functions that account for the shape and features of the t-distribution.

In this context, identifying the 10th percentile requires you to determine the t-value where only 10% of the distribution's data lies below it. This is crucial in scenarios like hypothesis testing, where understanding extremes can inform decision-making. The exact process involves statistical tools or software that can compute these values accurately. Understanding how to interpret and use percentile ranks is important in various fields, such as finance and scientific research.
Degrees of Freedom
The concept of degrees of freedom (df) is fundamental in statistics, especially when working with distributions like the t-distribution. Degrees of freedom are a measure of the number of values in a calculation that are free to vary.

In a t-distribution, degrees of freedom typically relate to the sample size. They influence the shape of the distribution curve: the fewer the degrees of freedom, the wider and more spread out the curve is. Conversely, with more degrees of freedom, the curve becomes more like the normal distribution.
Understanding degrees of freedom is crucial when you're interpreting statistical results, as it affects the accuracy and reliability of the conclusions derived from the data. Always consider the degrees of freedom in your data analysis to inform the selection of appropriate statistical tests and the interpretation of their outputs.
Statistical Function
Statistical functions are built-in tools in programming languages and software designed to perform specific statistical operations. They are crucial for automating and simplifying complex calculations.

For t-distributions, particularly, different programming environments offer specific functions to calculate percentiles. For example, Python offers the `scipy.stats.t.ppf` function, where "ppf" stands for percent point function, which reverses the cumulative distribution function to find the t-value for a given percentile.

In R, a popular statistical tool, the `qt` function serves a similar role. These functions require certain inputs, such as the desired percentile and degrees of freedom, to provide the correct result. Mastering these functions is essential for students and professionals who regularly analyze data, as it saves valuable time and reduces errors in computation.
Programming Tool
Using a programming tool effectively requires understanding its capabilities, especially for statistical tasks. Programming tools like Python and R excel because they offer extensive libraries and functions specifically for statistics and probability distributions.

Python, with its SciPy library, is incredibly powerful for handling statistical computations like the t-distribution. Its syntax is intuitive, and it allows users to perform complex calculations with relatively simple code. R, on the other hand, is a language crafted for statistical analysis, offering robust built-in functions such as `qt` to handle a wide array of statistical needs efficiently.

Choosing the right tool often depends on the specific task, user familiarity, and the problem at hand. Having a proficient understanding of these programming tools not only aids in performing accurate statistical analyses but also enhances data processing speed and precision.

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Most popular questions from this chapter

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Treatment with statins can reduce the risk of a major cardiovascular event in people with specified risk factors. During about 2 years of follow-up in the JUPITER trial (P. M. Ridker et al. \([8]), 142\) of 8901 subjects treated with a statin had a major cardiovascular event. Estimate the 2-year risk, and give a \(95 \%\) confidence interval for this estimate.

What will be the result if we conclude that the mean is greater than 45 when the actual mean is \(45 ?\) (i) We have made a type I error. (ii) We have made a type II error. (iii) We have made the correct decision.

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