Exam 4: A: Numerical Descriptive Techniques

Ages of Retirees A sociologist recently conducted a survey of retirees over 65 years of age whose net worth is too high to qualify for Medicaid and who have no private health insurance.The ages of 20 uninsured retirees were as follows: 65,66,67,68,69,70,71,73,74,75,78,79,80,81,86,87,91,92,94,and 97. -{Ages of Retirees Narrative} Describe the shape of the distribution of ages by comparing the quartiles.

Is a standard deviation of 10 a large number indicating great variability,or is it small number indicating little variability? To answer this question correctly,one should look carefully at the value of the:

If a data set is composed of 5 different numbers,there are ____________________ modes.

2-Year Investment Suppose you make a 2-year investment of $5,000 and it grows by 100% to $10,000 during the first year.During the second year,however,the investment suffers a 50% loss,from $10,000 back to $5,000. -{2-Year Investment Narrative} Calculate the arithmetic mean.

Weights of Teachers The following data represent the weights in pounds of a sample of 25 teachers: 164,148,137,157,173,156,177,172,169,165,145,168,163,162,174,152,156,168,154,151,174,146,134,140,and 171. -{Weights of Teachers Narrative} Compute the range and coefficient of variation.

If the mean,median,and mode are all equal,the histogram must be symmetric and bell shaped.

There are three measures of central location;the mean,the ____________________,and the ____________________.

Chebysheff's Theorem states that the percentage of measurements in a data set that fall within three standard deviations of their mean is:

Weights of Police Officers The following data represent the weights in pounds of a sample of 25 police officers: 164,148,137,157,173,156,177,172,169,165,145,168,163,162,174,152,156,168,154,151,174,146,134,140,and 171. -{Weights of Police Officers Narrative} Determine the location and value of the 60th percentile of the weights.

The data set 10,20,30 has the same variance as the data set 100,200,300.

____________________ uses both the mean and the standard deviation to interpret standard deviation for histograms of any shape.

Which of the following summary measures is affected most by extreme values?

Which of the following statements is true for the following observations: 9,8,7,9,6,11,and 13?

The Empirical Rule states that the percentage of observations in a data set (providing that the data set is bell shaped)that fall within one standard deviation of their mean is approximately 75%.

Any points that lie outside the whiskers on a box plot are called ____________________.

In symmetric data,the value for Q₂ is always halfway between Q₁ and Q₃.

The ____________________ is the least desirable of all the measures of central location.

Ages of Retirees A sociologist recently conducted a survey of retirees over 65 years of age whose net worth is too high to qualify for Medicaid and who have no private health insurance.The ages of 20 uninsured retirees were as follows: 65,66,67,68,69,70,71,73,74,75,78,79,80,81,86,87,91,92,94,and 97. -{Ages of Retirees Narrative} What does the value of the third quartile tell you?

The smaller the spread of scores around the mean:

A data sample has a mean of 107,a median of 122,and a mode of 134.The distribution of the data is positively skewed.