Eco ch. 3
In a symmetric frequency distribution, the mean and median are equal.
true
The range is based on 2 observations in your data.
true
The sample mean is based on fewer observations than the population mean.
true
The sample standard deviation is s=1.5s=1.5. This implies that σ2σ2 is equal to
unknown
Suppose the population variance is σ2=25σ2=25. Then
σ=5
In a sample of 20 friends, 12 have blue eyes. The sample proportion of blue eyes is:
60%
The mean of 6, 13, and 5 is:
8
Suppose you have 4 observations: 9, 6, 15 and 10. The median is
9.5
Suppose you have a sample of 11 observations. The median is ______ in the ordered list.
the 6th observation
Suppose that the population had a 5th observation, x5=12x5=12, in addition to the observations in the table above. The variance is then
4.8
Suppose you have a population with N = 3 observations and x1=x2=x3=5x1=x2=x3=5. The population variance is:
0
In a sample of 50 people, the proportion of those with blue eyes is 32%. How many people in the sample have blue eyes?
16
Suppose that x1 = 5, x2 = 3, x3 = 1, x4 = -2 and x5 = 4. Then ∑5i=3xi∑i=35xi is equal to
3
Data that provide labels or names for groupings of like items are known as
categorical data
A set of observations either has no mode, or multiple modes.
false
In a left-skewed distribution, the median is less than the mean.
false
The mean is always equal to one of your data values
false
The median is sensitive to outliers.
false
The median tells you something about the amount of variation in your observations, but the mean does not.
false
The sample variance can be negative.
false
The median of a set of observations is the ____ value
middle
Which of the following graphical methods is most appropriate for categorical data?
pie chart