/*! 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 57 There are two common methods for... [FREE SOLUTION] | 91Ó°ÊÓ

91Ó°ÊÓ

There are two common methods for measuring the concentration of a pollutant in fish tissue. Do the two methods differ, on average? You apply both methods to each fish in a random sample of 18 carp and use (a) the paired \(t\) test for \(\mu_{d}\) (b) the one-sample \(z\) test for \(p\). (c) the two-sample \(t\) test for \(\mu_{1}-\mu_{2}\). (d) the two-sample \(z\) test for \(p_{1}-p_{2}\). (e) none of these.

Short Answer

Expert verified
(a) the paired t test for \( \mu_{d} \).

Step by step solution

01

Identifying the Problem Type

We need to determine if the two methods for measuring concentration differ, on average, using statistical tests. Since the same fish undergoes both methods, this suggests a paired comparison is appropriate.
02

Selecting the Correct Test

Given the problem involves applying two measurement methods to the same subjects (the carp fish), it naturally leads us to consider differences for each pair of measurements. This setup aligns with using a paired \( t \) test, as it evaluates the mean difference between paired observations.
03

Evaluating Test Choices

Let's evaluate the options:- (a) The paired \( t \) test is suitable for paired data as discussed.- (b) The one-sample \( z \) test for \( p \) is applied to proportion data, which doesn't fit our case.- (c) The two-sample \( t \) test assumes two independent samples, whereas we have paired data.- (d) The two-sample \( z \) test for \( p_{1}-p_{2} \) is also used for proportions and independent samples.- (e) None of these suggests none are suitable, which isn't true since option (a) fits.
04

Making the Final Decision

Based on the pairing of data and the type of measurements, the paired \( t \) test is appropriately used to analyze whether the two methods differ on average. Therefore, choice (a) is the correct method.

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Key Concepts

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

Statistical Tests
Statistical tests are important tools in data analysis that help us make decisions about our data. They help us determine if there are differences between groups or if results are due to chance. In the context of our exercise, different statistical tests were considered to evaluate if two pollutant measurement methods in fish tissue differed.
  • Paired t-test: This test is specifically designed for comparing two related samples. Here, each fish is tested using both methods, making it suitable to evaluate the mean difference between paired observations. By examining these differences, we can determine if the average measurement differs between the two methods.
  • One-sample z-test: Typically used for testing the mean of a single sample against a population mean, it focuses on proportions rather than means of paired differences. Thus, this test doesn’t fit our scenario.
  • Two-sample t-test: Ideal for comparing means from two independent groups. In our case, however, each fish undergoes both tests, making them not independent but rather a pair.
  • Two-sample z-test: Primarily concerned with proportions of two independent samples, and hence not applicable here as we are dealing with paired data.
Understanding these tests helps in selecting the correct analysis method for different data sets.
Measurement Method Comparison
When comparing measurement methods, it's crucial to have a systematic approach to assess whether two methods yield different results. This exercise specifically involves measuring pollutant concentration in fish, and two methods were tested on the same sample of fish.
  • Ensuring Accuracy: Applying both methods to each fish helps in minimizing external variability. This is because any biological differences across different subjects are eliminated since the same subject is used in both methods.
  • Identifying Discrepancies: The use of paired measurements helps in detecting actual discrepancies between method results rather than just random variance from different subjects.
  • Analyzing Differences: Through statistical analyses like paired t-tests, you can confidently assess whether there is a significant difference in results, aiding in selecting the better method for accurate readings.
This approach ensures that the chosen method reliably represents the pollutant levels in fish, facilitating accurate environmental analyses.
Data Analysis in Statistics
Data analysis is a crucial step in extracting meaningful conclusions from raw data. In statistic exercises like the one described, it's all about understanding the story behind the numbers through proper analysis.
  • Data Collection: The first step involves gathering data through consistent experiments, such as applying two measurement methods to the same fish. Accurate data collection is key to useful analysis.
  • Descriptive Analysis: Describing and summarizing the collected data, including assessing the mean or average pollutant level determined by each method, helps in understanding basic patterns and variations.
  • Inferential Analysis: This goes a step further by applying statistical tests (like the paired t-test in our case) to infer whether observed patterns are statistically significant. This helps in making informed decisions based on sample data.
Through structured data analysis, we can validate assumptions, test hypotheses, and ultimately reach sound conclusions that back scientific and practical decision-making.

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Most popular questions from this chapter

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