Chapter 3 Weighted Mean
36.294*2 +- 588 of 1365
A company produces a lightweight valve. The weights of the valves produced are normally distributed with a mean weight of 1365 grams and a standard deviation of 294 grams. Within what range would approximately 95% of the valve weights fall? _____________________________
1.
A distribution of numbers is approximately bell shaped. If the mean of the numbers is 125 and the standard deviation is 12, between what two numbers would approximately 68% of the values be? Between what two numbers would 95% of the values be? Between what two values would 99.7% of the values be?
31.2.5sqr k2=6.5 1/6.25=.16 c1-.16=84
According to Chebyshev's Theorem at least ______________% of all values are within 2.5 standard deviations of the mean.
32.2.56
According to Chebyshev's Theorem, at least what proportion of the data will be within 1.6 standard deviations of the mean? ______________________
34.
According to Chebyshev's Theorem, how many standard deviations from the mean would include at least 80% of the values?
25.dollars
If data is measured in dollars, then the computed variance would have units of _________________________________.
9.spread
Measures of dispersion give an idea of the amount of _____________________ in data.
What is the value of k2? ________ What is the value of 1/k2? _____________ What is 1-1/k2? _____________________
2sqr k2= 4 1/4=.75 c 1-.75=.25
24.standard deviation
If data is measured in units of degrees Fahrenheit, then the computed variance would have units of _______________________________.
8.skew to the right>
If the mean of a data set equals 58, the median equals 21, and the mode equals 8, the distribution is ___________________________(shape).
7.skew to the left<
If the mean of a data set equals 69, the median equals 74, and the mode equals 129, the distribution is ___________________________ (shape).
6.Negitive
In a __________________________ distribution, the mode is larger than the median, and the median is larger than the mean.
4.semetric
In a ___________________________ distribution, the mean, median, and mode are equal.
5.Postive
In a _______________________________________ distribution, the mean is larger than the median, and the median is larger than the mode.
22.population and sample
N represents _______________________ while n represents _____________________.
75, 2
Specifically, Chebyshev's theorem says that at least ______% of all values are within 2 standard deviations of the mean. First ask, what is the value of k, the number of standard deviations? _______
33.
Suppose the average age of a professional employed by a particular computer firm is 28 with a standard deviation of 5 years. Apply Chebyshev's theorem to determine within what range of ages at least 85% of the workers' ages fall.
35.68%,95%,99.7%
The Empirical Rule states that for a symmetrical, bell-shaped curve, at least _________% of the observations will be within 1 standard deviation of the mean; __________% of the observations will be within 2 standard deviations of the mean; and ____________% of the observations will be within 3 standard deviations of the mean.
12. Mean Deviation
The _______________________ measures the mean amount by which the values in a population, or sample, vary from the mean.
26.standard deviation
The _______________________________ is the square root of variance.
16.0
The absolute value signs are used when computing mean deviation because without them the sum of the deviations from the mean equals _________________________.
11.largest to small
The calculated range is based on ______________ values.
13.MD= e[x--xbar]/N
The formula for mean deviation is:
20.o2= E(x-u)2/N
The formula for population variance is:
21.s2=E(x-U)2/n-1
The formula for sample variance is:
2.-xw= w1x1+w2x2+w3x3/w1+w2+w3=
The formula for the weighted mean is:
10.range 20,30, 40,50,60,70,80 = 60
The mathematical difference in the largest value and smallest value in a data set is called the ______________________.
27.o
The symbol for population standard deviation is ____________.
18.02
The symbol for population variance is _________________.
28.s
The symbol for sample standard deviation is __________.
19.S2
The symbol for sample variance is ______________________.
14.sigma adding
The symbol Σ means __________________________.
3.Range large to small, Mean Deviation md=E[x--x]/n varince and standard deviation
The three shapes of distributions are ___________________________, ____________________________, and ____________________________.
2.
The time needed to assemble a particular piece of furniture with experience is normally distributed with a mean time of 43 minutes. If 68% of the assembly times are between 40 and 46 minutes, what is the value of the standard deviation? Suppose 99.7% of the assembly times are between 35 and 51 minutes and the mean is still 43 minutes. What would the value of the standard deviation be now?
1.Several , value
The weighted mean is a special case of the arithmetic mean, it occurs only when there are _______________ observations of the same __________________.
15.[ ] absoulte value
The | | marks indicate ____________________________.
23.squared
Variance is difficult to interpret because the units are ______________________.
17.Variance
__________________________________ is the mean of the SQUARED deviations of the mean.
29.Chebyshey's theorem
___________________________________ states that for any set of observations, the proportion of the values that lie within k standard deviations of the mean is at least 1 - (1/k2), where k is any constant greater than 1. K is the number of __________________________________.
