Exam 3: Descriptive Statistics: Numerical Methods

A real estate appraiser is gathering housing sales data by street in the neighborhood in preparation for his next job.Listed below are the six streets and the average sales price and the houses sold in the last 12 months.Calculate the mean sales price for the neighborhood. Street Avg Sales Price Elm 159,999 1 Maple 210,998 6 Oak 185,000 4 Pine 202,632 4 Rose 175,500 5 Petunia 352,941 3

Suppose that a company's annual sales were $1,200,000 in 1999.The annual growth rate of sales from 1999 to 2000 was 16 percent,from 2000 to 2001 it was -5 percent,and from 2001 to 2002 it was 22 percent. The geometric mean growth rate of sales over this three-year period is calculated as 10.37 percent.Use the geometric mean growth rate and determine the forecasted sales for 2004.

In a statistics class,10 scores were randomly selected with the following results: 74,73,77,77,71,68,65,77,67,66 What is the 65^th percentile?

Z-score is often used as a measure of risk.

The marketing research department of a company was asked to respond to the CEO's question about the average age of consumers of the company's most profitable product.From survey data gathered two years ago,the researchers found the following table.Calculate the average age to give to the CEO. Midpt of Age Class N 17.5 23.5 65 29.5 100 35.5 220 41.5 250 52.5 120

Chebyshev's Theorem is only of practical use when analyzing a non-mound-shaped population that is not very skewed.

The line that minimizes the sum of the squared horizontal (x)distances between the points on the scatter plot and the line is the least squares line.

A random sample of 60 students in the business statistics course answered a survey on the average number of hours they spent on statistics each week.Unfortunately,the original data were lost and all that remains is the frequency table below.From these data,calculate the estimated sample standard deviation. Class Hrs N Midpt fM 1 0-3 18 1.5 27 2 4-7 16 5.5 88 3 8-11 14 9.5 133 4 12-15 10 13.5 135 5 16-19 17.5 60 418

In a hearing test,subjects estimate the loudness (in decibels)of a sound,and the results are: 68,67,70,71,68,75,68,62,80,73,68. What is the mean?

Find the z-score for an IQ test score of 125 when the mean is 100 and the standard deviation is 15.

The p^th percentile is a value such that (100 - p)percent of the measurements fall at or below the value.

The median is the value below which and above which approximately 50 percent of the measurements lie.

The population variance is the average of the squared deviations of the individual population measurements from the population mean.

The rate of return for each of the past four years on a market fund are R₁ = 2.4%,R₂ = 1.0%,R₃ = -3.2%,and R₄ = 0.5%.Find the geometric mean rate of return.

The average lateness for one of the top airline companies is 10 minutes.The variance of the lateness measure is calculated as 9.An airplane arrived 13 minutes after the stated arrival time.Calculate the z-score for this particular airplane's lateness.

The mean is one component of the five-number summary.

In a hearing test,subjects estimate the loudness (in decibels)of a sound,and the results are (mean = 70): 68,67,70,71,68,75,68,62,80,73,68 What is the range?

Which of the following is influenced the least by the occurrence of extreme values in a sample?

Find the z-score for an IQ test score of 92 when the mean is 100 and the standard deviation is 15.

An initial investment of $10,000 has a value of $7,382 at the end of year 1.What is the rate of return for the first year?