/*! 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 11 Houses in California are expensi... [FREE SOLUTION] | 91Ó°ÊÓ

91Ó°ÊÓ

Houses in California are expensive, especially on the Central Coast where the air is clear, the ocean is blue, and the scenery is stunning. The median home price in San Luis Obispo County reached a new high in July 2004, soaring to \(\$ 452,272\) from \(\$ 387,120\) in March 2004\. (San Luis Obispo Tribune, April 28,2004 ). The article included two quotes from people attempting to explain why the median price had increased. Richard Watkins, chairman of the Central Coast Regional Multiple Listing Services was quoted as saying, "There have been some fairly expensive houses selling, which pulls the median up." Robert Kleinhenz, deputy chief economist for the California Association of Realtors explained the volatility of house prices by stating: "Fewer sales means a relatively small number of very high or very low home prices can more easily skew medians." Are either of these statements correct? For each statement that is incorrect, explain why it is incorrect and propose a new wording that would correct any errors in the statement.

Short Answer

Expert verified
Statement one is potentially incorrect as expensive houses being sold won't necessarily raise the median unless these new prices replace the middle values. The correction would state that high-priced houses being sold may not influence the median unless they become the new middle values. Statement two is generally correct with fewer sales; a very high or low home price could shift the middle point, especially in a smaller data set, hence altering the median.

Step by step solution

01

Understanding The Concept of Median

The median is the middle value in a list of numbers. If the numbers were arranged in ascending order, the median is the number in the center; if there is an even number of values, the median is the simple average of the two central values.
02

Analyzing Statement One

The first statement claims that selling high-priced homes skew the median home price upwards. To determine whether this is accurate, consider the definition of the median. If a data set is correspondingly skewed by large values, the mean (average) could be affected; however, the median as the middle value is relatively impervious to extreme values on either the high or low end. Therefore, unless the expensive houses sold replace houses in the middle of the data set, they may not significantly shift the median upwards. Hence, the first statement could potentially be incorrect.
03

Analyzing Statement Two

The second statement claims that fewer sales and a few very high or very low home prices can skew medians. It's accurate to an extent, especially when dealing with small datasets (minimal number of homes sold). The median could change significantly because an extremely high or low value could shift the middle point of the data set. So, this statement is somewhat correct, especially in cases of minimal sales. Nevertheless, it is much more likely to affect the mean (or average) than the median.
04

Propose Amendment to Incorrect Statement

Since the first statement could potentially be incorrect, an amendment could be 'High-priced homes being sold within the data set might not necessarily pull the median up, unless these prices become the middle value in the ordered set of all home prices, thereby affecting the median.'

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.

Home Price Analysis
When discussing home prices, especially in areas like San Luis Obispo County, understanding the median price is essential in capturing the market trends. The median home price is a measure of central tendency, which helps represent the typical price homebuyers may encounter. By focusing on the median price rather than the average, analysts can understand the market without the skew of extremely high or low house prices that might influence the mean. This is particularly useful in regions where luxury homes or distressed properties might be on either end of the price spectrum.

In the case of San Luis Obispo County in 2004, when the median price increased significantly, there could be multiple interpretations, such as a genuine uptick in overall market value or a change in the price distribution of homes sold during that period.

  • An increase in the median could indicate a general rise in property values in the area.
  • Alternatively, it might suggest differences in the types of properties being sold, such as a higher number of mid-to-high-priced homes.
By analyzing median home prices, stakeholders can better understand whether they're witnessing long-term growth or temporary fluctuations due to market anomalies.
Central Tendency Measures
Central tendency measures are statistics used to gauge the center point of a data set, with the most common being the mean, median, and mode. Each of these has unique properties and usefulness in different scenarios.

The mean, or average, is calculated by adding all data points together and dividing by the number of points. While useful, the mean can be heavily influenced by outliers.

The median, unlike the mean, identifies the middle value in an ordered list and is resistant to extreme values, making it valuable in situations with skewed data or outliers, such as home pricing.

The mode is the value that appears most frequently, which might not always be relevant in datasets with unique values.
  • In home price analysis, the median is often more reliable than the mean as it does not get swayed by unusually low or high-priced homes.
  • When analyzing pricing trends or making financial projections, choosing the right measure of central tendency is crucial for accuracy.
Understanding these concepts aids in making informed decisions about the housing market and interpreting data with a nuanced approach.
Data Skewness
Data skewness refers to the asymmetry in the distribution of values within a dataset. When analyzing real estate prices, skewness is a critical factor, as it affects how the distribution of home prices can appear, influencing statistical measures used by analysts.

A dataset is skewed if it is not symmetrical—this often occurs in real estate markets. For instance:

  • Positive skewness occurs when a few high-priced homes pull the distribution's tail to the right. In such cases, the mean will be greater than the median.
  • Negative skewness is rarer in real estate and occurs when low-priced properties skew the data to the left.
Recognizing skewness is essential because it informs which statistical measures are most appropriate to use. For example, in real estate, since positively skewed data is common, the median tends to provide a better sense of central tendency than the mean.

Understanding skewness aids stakeholders in interpreting market conditions correctly and can help in discerning whether trends in pricing are reflective of actual value changes or merely shifts in the type of homes currently being transacted.

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

The standard deviation alone does not measure relative variation. For example, a standard deviation of \(\$ 1\) would be considered large if it is describing the variability from store to store in the price of an ice cube tray. On the other hand, a standard deviation of \(\$ 1\) would be considered small if it is describing store-to-store variability in the price of a particular brand of freezer. A quantity designed to give a relative measure of variability is the coefficient of variation. Denoted by CV, the coefficient of variation expresses the standard deviation as a percentage of the mean. It is defined by the formula \(C V=100\left(\frac{s}{\bar{x}}\right)\). Consider two samples. Sample 1 gives the actual weight (in ounces) of the contents of cans of pet food labeled as having a net weight of 8 ounces. Sample 2 gives the actual weight (in pounds) of the contents of bags of dry pet food labeled as having a net weight of 50 pounds. The weights for the two samples are \(\begin{array}{lrrrrr}\text { Sample 1 } & 8.3 & 7.1 & 7.6 & 8.1 & 7.6 \\ & 8.3 & 8.2 & 7.7 & 7.7 & 7.5 \\ \text { Sample 2 } & 52.3 & 50.6 & 52.1 & 48.4 & 48.8 \\ & 47.0 & 50.4 & 50.3 & 48.7 & 48.2\end{array}\) a. For each of the given samples, calculate the mean and the standard deviation. b. Compute the coefficient of variation for each sample. Do the results surprise you? Why or why not?

The accompanying data on number of minutes used for cell phone calls in one month was generated to be consistent with summary statistics published in a report of a marketing study of San Diego residents (TeleTruth, March 2009): $$ \begin{array}{rrrrrrrrrr} 189 & 0 & 189 & 177 & 106 & 201 & 0 & 212 & 0 & 306 \\ 0 & 0 & 59 & 224 & 0 & 189 & 142 & 83 & 71 & 165 \\ 236 & 0 & 142 & 236 & 130 & & & & & \end{array} $$ a. Would you recommend the mean or the median as a measure of center for this data set? Give a brief explanation of your choice. (Hint: It may help to look at a graphical display of the data.) b. Compute a trimmed mean by deleting the three smallest observations and the three largest observations in the data set and then averaging the remaining 19 observations. What is the trimming percentage for this trimmed mean? c. What trimming percentage would you need to use in order to delete all of the 0 minute values from the data set? Would you recommend a trimmed mean with this trimming percentage? Explain why or why not.

The report "Who Moves? Who Stays Put? Where's Home?" (Pew Social and Demographic Trends, December 17,2008 ) gave the accompanying data for the 50 U.S. states on the percentage of the population that was born in the state and is still living there. The data values have been arranged in order from largest to smallest. \(\begin{array}{lllllllllll}75.8 & 71.4 & 69.6 & 69.0 & 68.6 & 67.5 & 66.7 & 66.3 & 66.1 & 66.0 & 66.0\end{array}\) \(\begin{array}{lllllllllll}65.1 & 64.4 & 64.3 & 63.8 & 63.7 & 62.8 & 62.6 & 61.9 & 61.9 & 61.5 & 61.1\end{array}\) \(\begin{array}{lllllllllll}59.2 & 59.0 & 58.7 & 57.3 & 57.1 & 55.6 & 55.6 & 55.5 & 55.3 & 54.9 & 54.7\end{array}\) \(\begin{array}{lllllllllll}54.5 & 54.0 & 54.0 & 53.9 & 53.5 & 52.8 & 52.5 & 50.2 & 50.2 & 48.9 & 48.7\end{array}\) \(\begin{array}{llllll}48.6 & 47.1 & 43.4 & 40.4 & 35.7 & 28.2\end{array}\) a. Find the values of the median, the lower quartile, and the upper quartile. b. The two smallest values in the data set are \(28.2\) (Alaska) and \(35.7\) (Wyoming). Are these two states outliers? c. Construct a boxplot for this data set and comment on the interesting features of the plot.

Consumer Reports Health (www.consumer reports.org/health) reported the sodium content \((\mathrm{mg})\) per 2 tablespoon serving for each of 11 different peanut butters: $$ \begin{array}{rrrrrrrr} 120 & 50 & 140 & 120 & 150 & 150 & 150 & 65 \\ 170 & 250 & 110 & & & & & \end{array} $$ a. Display these data using a dotplot. Comment on any unusual features of the plot. b. Compute the mean and median sodium content for the peanut butters in this sample. c The values of the mean and the median for this data set are similar. What aspect of the distribution of sodium content -as pictured in the dotplot from Part (a) - provides an explanation for why the values of the mean and median are similar?

Based on a large national sample of working adults, the U.S. Census Bureau reports the following information on travel time to work for those who do not work at home: lower quartile \(=7\) minutes median \(=18\) minutes upper quartile \(=31\) minutes Also given was the mean travel time, which was reported as \(22.4\) minutes. a. Is the travel time distribution more likely to be approximately symmetric, positively skewed, or negatively skewed? Explain your reasoning based on the given summary quantities. b. Suppose that the minimum travel time was 1 minute and that the maximum travel time in the sample was 205 minutes. Construct a skeletal boxplot for the travel time data. c Were there any mild or extreme outliers in the data set? How can you tell?

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.