Stats assignment 3
A sample of small bottles and their contents has the following weights (in grams): 4, 2, 5, 4, 5, 2, and 6. What is the sample variance of bottle weight?
2.33
The weights of a sample of crates ready for shipment to Moscow, Russia are (in kilograms): 103, 97, 101, 106, and 103. What is the mean deviation?
2.4 kg
What is the median of 26, 30, 24, 32, 32, 31, 27, and 29?
29.5
Ten experts rated a newly developed chocolate chip cookie on a scale of 1 to 50. Their ratings were: 34, 35, 41, 28, 26, 29, 32, 36, 38, and 40. What is the mean deviation of the ratings?
4.12
According to Chebyshev's Theorem, at least what percent of the observations lie within plus and minus 1.75 standard deviations of the mean?
67%
On a finance exam, 15 accounting majors had an average grade of 90. On the same exam, 7 marketing majors averaged 85, and 10 finance majors averaged 93. What is the weighted mean for all 32 students taking the exam?
89.84
The mean, as a measure of central location, would be inappropriate for which one of the following?
Marital status of college students at a particular university
The sum of the deviations of each data value from this measure of central location will always be zero.
Mean
For any data set, which measures of central location have only one value?
Mean and median
Which measures of central location are not affected by extremely small or extremely large values?
Mode and Median
Which of the following measures of dispersion are based on deviations from the mean?
all apply
A sample of assistant professors on the business faculty at state-supported institutions in Ohio revealed the mean income to be $72,000 for nine months, with a standard deviation of $3,000. Using Chebyshev's Theorem, what proportion of the faculty earns more than $66,000, but less than $78,000?
at least 75%
What is a disadvantage of the range as a measure of dispersion?
it is based on only two observations.
For a data set, half of the observations are always greater than the
median
If the variance of the "number of daily parking tickets issued is 100, the standard deviation is defined as the
square root of the variance of the "number of daily parking tickets"
What is the relationship between the variance and the standard deviation?
variance is the square of the standard deviation
The sum of the differences between sample observations and the sample mean is equal to
zero
Which one of the following is referred to as the population mean
µ
The monthly amounts spent for food by families of four receiving food stamps approximates a symmetrical, normal distribution. The sample mean is $150 and the standard deviation is $20. Using the Empirical Rule, about 95% of the monthly food expenditures are between what two amounts?
$110 and $190
For a sample of similar sized all-electric homes, the March electric bills were: $212, $191, $176, $129, $106, $92, $108, $109, $103, $121, $175, and $194. What is the range?
$120
The following are the weekly amounts of welfare payments made by the federal government to a sample of six families: $139, $136, $130, $136, $147, and $136. What is the range?
$17
a stockbroker placed the following order for a customer: 50 shares of Kaiser Aluminum at $104 a share 100 shares of GTE at $25.25 a share 20 shares of Boston Edison at $9.125 a share What is the weighted arithmetic mean price per share?
$46.51
During the past six months, a purchasing agent placed the following three orders for coal: What is the weighted arithmetic mean price per ton?
$72.33
The net incomes (in $millions) of a sample of steel fabricators are $86, $67, $86, and $85. What is the modal net income?
$86
The weights (in thousands of kilograms) of seven shipping containers are 9.5, 10.3, 11.0, 10.4, 10.5, 11.2, and 9.2. What is the mean deviation?
.543 kg
The distribution of a sample of the outside diameters of PVC pipes approximates a symmetrical, bell-shaped distribution. The arithmetic mean is 14.0 inches, and the standard deviation is 0.1 inches. About 68% of the outside diameters lie between what two amounts?
13.9 and 14.1 inches