Intro to Stat 2.1
A _____ lists each category of data and the number of occurrences for each category of data.
Frequency distribution
A frequency distribution lists the ________ of occurrences of each category of data, while a relative frequency distribution lists the _______ of occurrences of each category of data.
number ; proportion
A phlebotomist draws the blood of a random sample of 50 patients and determines their blood types as shown. A phlebotomist draws the blood of a random sample of 50 patients and determines their blood types as shown. Use the results of the sample to conjecture the percentage of the population that has type O blood. Is this an example of descriptive or inferential statistics? Contact a local hospital and ask them the percentage of the population that is blood type O. Why might the results differ?
44%; inferential ; The results might differ because there is always a chance that the sample surveyed is unlike the population.
A phlebotomist draws the blood of a random sample of 50 patients and determines their blood types as shown. Construct a relative frequency distribution. According to the data, which blood type is most common? According to the data, which blood type is least common?
A - 0.36 AB - 0.08 B - 0.12 O - 0.44 ; O ; AB
A _______ is constructed by labeling each category of data on either the horizontal or vertical axis and the frequency or relative frequency of the category on the other axis. Rectangles of equal width are drawn for each category. The height of each rectangle represents the category's frequency or relative frequency.
Bar graph
The _________ is the proportion (or percent) of observations within a category and is found using the formula
Relative frequency ; Relative frequency=Frequency /Sum of all frequencies
A ____________ lists each category of data together with the relative frequency.
Relative frequency distribution
In a relative frequency distribution, what should the relative frequencies add up to?
The relative frequencies add up to 1 ; A relative frequency distribution lists each category of data together with the relative frequency. The frequency column sums to the total number of observations. The relative frequency is the proportion (or percent) of observations within a category.
