/*! 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 14 Archaeology: Pottery Santa Fe bl... [FREE SOLUTION] | 91Ó°ÊÓ

91Ó°ÊÓ

Archaeology: Pottery Santa Fe black-on-white is a type of pottery commonly found at archaeological excavations in Bandelier National Monument. At one excavation site a sample of 592 potsherds was found, of which 360 were identified as Santa Fe black-on-white (Bandelier Archaeological Excavation Project: Summer 1990 Excavations at Burnt Mesa Pueblo and Casa del Rito, edited by Kohler and Root, Washington State University). (a) Let \(p\) represent the population proportion of Santa Fe black-on-white potsherds at the excavation site. Find a point estimate for \(p\). (b) Find a \(95 \%\) confidence interval for \(p .\) Give a brief statement of the meaning of the confidence interval. (c) Check Requirements Do you think the conditions \(n p>5\) and \(n q>5\) are satisfied in this problem? Why would this be important?

Short Answer

Expert verified
(a) Point estimate \( \hat{p} = 0.608 \). (b) 95% CI: \( (0.569, 0.647) \). (c) Conditions \( np > 5 \) and \( nq > 5 \) are satisfied.

Step by step solution

01

Calculate the Point Estimate

The point estimate for the population proportion \( p \) of Santa Fe black-on-white potsherds is given by the sample proportion \( \hat{p} \). This can be calculated using the formula: \( \hat{p} = \frac{x}{n} \), where \( x \) is the number of Santa Fe black-on-white potsherds, and \( n \) is the total number of potsherds in the sample.Substituting the given values:\[ \hat{p} = \frac{360}{592} \approx 0.608 \]
02

Calculate the 95% Confidence Interval

The 95% confidence interval for the population proportion \( p \) can be calculated using the formula: \( \hat{p} \pm z \times \sqrt{\frac{\hat{p}(1-\hat{p})}{n}} \), where \( z \) is the z-score for a 95% confidence level (approximately 1.96).First, calculate the standard error:\[ \sqrt{\frac{0.608 \times (1 - 0.608)}{592}} \approx 0.020 \]Now, find the confidence interval:\[ 0.608 \pm 1.96 \times 0.020 \approx 0.608 \pm 0.039 \]Thus, the 95% confidence interval for \( p \) is approximately \( (0.569, 0.647) \).
03

Interpret the Confidence Interval

The confidence interval \( (0.569, 0.647) \) means that we are 95% confident that the true proportion of Santa Fe black-on-white potsherds at the site lies between 56.9% and 64.7%.
04

Check Requirements

The requirements \( n p > 5 \) and \( n q > 5 \) need to be checked to justify the normal approximation method used in the confidence interval calculation.Calculate \( np \) and \( nq \):\[ n \times \hat{p} = 592 \times 0.608 = 360.736 \]\[ n \times (1-\hat{p}) = 592 \times 0.392 = 231.264 \]Both values are greater than 5, so the conditions are satisfied. This is important because it validates using a normal approximation for constructing the confidence interval.

Unlock Step-by-Step Solutions & Ace Your Exams!

  • Full Textbook Solutions

    Get detailed explanations and key concepts

  • Unlimited Al creation

    Al flashcards, explanations, exams and more...

  • Ads-free access

    To over 500 millions flashcards

  • Money-back guarantee

    We refund you if you fail your exam.

Over 30 million students worldwide already upgrade their learning with 91Ó°ÊÓ!

Key Concepts

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

Archaeology Statistics
In archaeology, statistics often play a vital role in interpreting findings from excavation sites. Archaeologists collect data, like pottery shards, and use statistical methods to analyze them. This helps provide insights into ancient cultures. For instance, analyzing the proportion of specific types of pottery found, like the Santa Fe black-on-white potsherds, can reveal information about the historical period or cultural practices of the site's inhabitants. When archaeologists use statistics, they rely on both descriptive statistics to summarize data and inferential statistics to make predictions or inferences about a population based on a sample. Inferential statistics include methods like confidence intervals, which offer insights into how a certain characteristic might be distributed across a larger population, given the data collected from a sample. This is crucial in archaeological studies where examining the total population is often impossible.
Population Proportion
Population proportion is a statistical measure that describes the fraction of the population that possesses a particular characteristic. In our archaeological context, it represents the proportion of Santa Fe black-on-white potsherds in the entire excavation site. The population proportion is often symbolized by \( p \) and can only be determined by examining every single piece in the population, which is usually impractical. Instead, a common approach is to estimate this proportion using data from a sample, known as a point estimate. The sample proportion, symbolized by \( \hat{p} \), serves as this estimate and provides valuable insights into the broader population when the entire population is inaccessible.This concept is crucial because it helps archaeologists infer the prevalence of certain cultural artifacts without needing to analyze the entire population. Understanding the population proportion is key for developing broader historical insights from a subset of an excavation.
Normal Approximation
Normal approximation is a statistical technique used to simplify the process of making inferences about a population proportion. It enables the use of normal distribution to approximate the distribution of the sample proportion, which is particularly useful when calculating confidence intervals. For the approximation to be valid, certain conditions must be met: \( np > 5 \) and \( nq > 5 \), where \( n \) is the sample size, \( p \) is the sample proportion, and \( q = 1-p \). These conditions ensure the sample is large enough for the normal distribution to be an accurate approximation.In this archaeological example, both conditions are satisfied, meaning a normal approximation is appropriate for the confidence interval calculation, providing a reliable estimate for the population proportion of potsherds.
Sample Proportion
The sample proportion \( \hat{p} \) is a key element in estimating the population proportion. It is derived by dividing the number of occurrences of a particular characteristic (e.g., Santa Fe black-on-white potsherds) by the total number of observations in the sample.In the given archaeological study, the sample proportion is calculated by taking the number of Santa Fe black-on-white potsherds (360) and dividing it by the total potsherds found (592), yielding approximately 0.608.This measure is fundamental for statistical analysis as it serves as the basis for creating confidence intervals and other inferential statistics. By understanding the sample proportion, archaeologists can draw conclusions about the broader population, which helps in reconstructing historical contexts.

One App. One Place for Learning.

All the tools & learning materials you need for study success - in one app.

Get started for free

Most popular questions from this chapter

Confidence Intetvals: Values of \(\sigma\) A random sample of size 36 is drawn from an \(x\) distribution. The sample mean is \(100 .\) (a) Suppose the \(x\) distribution has \(\sigma=30\). Compute a \(90 \%\) confidence interval for \(\mu\). What is the value of the margin of error? (b) Suppose the \(x\) distribution has \(\sigma=20\). Compute a \(90 \%\) confidence interval for \(\mu\). What is the value of the margin of error? (c) Suppose the \(x\) distribution has \(\sigma=10\). Compute a \(90 \%\) confidence interval for \(\mu\). What is the value of the margin of error? (d) Compare the margins of error for parts (a) through (c). As the standard deviation decreases, does the margin of error decrease? (e) Critical Thinking Compare the lengths of the confidence intervals for parts (a) through (c). As the standard deviation decreases, does the length of a \(90 \%\) confidence interval decrease?

Uric Acid Overproduction of uric acid in the body can be an indication of cell breakdown. This may be an advance indication of illness such as gout, leukemia, or lymphoma (Reference: Manual of Laboratory and Diagnostic Tests by \(\mathrm{F}\). Fischbach). Over a period of months, an adult male patient has taken eight blood tests for uric acid. The mean concentration was \(\bar{x}=5.35 \mathrm{mg} / \mathrm{d}\). The distribution of uric acid in healthy adult males can be assumed to be normal, with \(\sigma=1.85 \mathrm{mg} / \mathrm{d}\) l. (a) Find a \(95 \%\) confidence interval for the population mean concentration of uric acid in this patient's blood. What is the margin of error? (b) What conditions are necessary for your calculations? (c) Interpret Compare your results in the context of this problem. (d) Sample Size Find the sample size necessary for a \(95 \%\) confidence level with maximal margin of error \(E=1.10\) for the mean concentration of uric acid in this patient's blood.

Baseball: Home Run Percentage The home run percentage is the number of home runs per 100 times at bat. A random sample of 43 professional baseball players gave the following data for home run percentages (Reference: The Baseball Encyclopedia, Macmillan). $$ \begin{array}{llllllllll} 1.6 & 2.4 & 1.2 & 6.6 & 2.3 & 0.0 & 1.8 & 2.5 & 6.5 & 1.8 \\ 2.7 & 2.0 & 1.9 & 1.3 & 2.7 & 1.7 & 1.3 & 2.1 & 2.8 & 1.4 \\ 3.8 & 2.1 & 3.4 & 1.3 & 1.5 & 2.9 & 2.6 & 0.0 & 4.1 & 2.9 \\ 1.9 & 2.4 & 0.0 & 1.8 & 3.1 & 3.8 & 3.2 & 1.6 & 4.2 & 0.0 \\ 1.2 & 1.8 & 2.4 & & & & & & & \end{array} $$ (a) Use a calculator with mean and standard deviation keys to verify that \(\bar{x} \approx 2.29\) and \(s \approx 1.40\). (b) Compute a \(90 \%\) confidence interval for the population mean \(\mu\) of home run percentages for all professional baseball players. Hint: If you use Table 6 of Appendix II, be sure to use the closest \(d . f\). that is smaller. (c) Compute a \(99 \%\) confidence interval for the population mean \(\mu\) of home run percentages for all professional baseball players. (d) Interpretation The home run percentages for three professional players are Tim Huelett, \(2.5 \quad\) Herb Hunter, \(2.0 \quad\) Jackie Jensen, \(3.8\) Examine your confidence intervals and describe how the home run percentages for these players compare to the population average. (e) Check Requirements In previous problems, we assumed the \(x\) distribution was normal or approximately normal. Do we need to make such an assumption in this problem? Why or why not? Hint: See the central limit theorem in Section \(6.5\).

Answer true or false. Explain your answer. If the sample mean \(\bar{x}\) of a random sample from an \(x\) distribution is relatively small, then the confidence interval for \(\mu\) will be relatively short.

Assume that the population of \(x\) values has an approximately normal distribution. Diagnostic Tests: Total Calcium Over the past several months, an adult patient has been treated for tetany (severe muscle spasms). This condition is associated with an average total calcium level below \(6 \mathrm{mg} / \mathrm{dl}\) (Reference: Manual of Laboratory and Diagnostic Tests by F. Fischbach). Recently, the patient's total calcium tests gave the following readings (in \(\mathrm{mg} / \mathrm{d}\) l). $$ \begin{array}{rrrrrrr} 9.3 & 8.8 & 10.1 & 8.9 & 9.4 & 9.8 & 10.0 \\ 9.9 & 11.2 & 12.1 & & & & \end{array} $$ (a) Use a calculator to verify that \(\bar{x}=9.95\) and \(s \approx 1.02\). (b) Find a \(99.9 \%\) confidence interval for the population mean of total calcium in this patient's blood. (c) Interpretation Based on your results in part (b), does it seem that this patient still has a calcium deficiency? Explain.

See all solutions

Recommended explanations on Math Textbooks

View all explanations

What do you think about this solution?

We value your feedback to improve our textbook solutions.

Study anywhere. Anytime. Across all devices.