Stats chapters 1-2
Heights of adult males are known to have a normal distribution. A researcher claims to have randomly selected adult males and measured their heights with the resulting relative frequency distribution as shown here. Identify two major flaws with these results
-All of the relative frequencies appear to be roughly the same. If they are from a normal distribution, they should start low, reach a maximum, and then decrease. -The sum of the relative frequencies is 127%, but it should be 100%, with a small possible round-off error.
in a test of a method of gender selection 663 couples used the xsort method and 424 of them bad baby girls
A discrete data set because there are a finite number of possible values
Which of the following is associated with a parameter?
Data that were obtained from an entire population.
Which of the following consists of discrete data? -Amount of rainfall -Tree height -Hair color -Number of suitcases on plane
Number of suitcases on plane
determine whether the given value is a statistic or a parameter. a sample of seniors is selected and it i found that 40% own a computer
Statistic because the value is a numerical measurement describing a characteristic of a sample.
In a set of data, blood lead levels are represented as 10 for low, 20 for medium, and 30 for high. The average (mean) of the 529 blood lead levels is 25.4. Identify the level of measurement of the data. Explain what is wrong with the given calculation.
The data are at the ordinal level of measurement. Such data should not be used for calculations such as an average.
determine whether the data described below are qualitative or quantitative and explain why. the types of food served by restaurants
The data are qualitative because they don't measure or count anything.
Ratings of hotels on a scale from 1 star to 7 stars
The ordinal level of measurement is most appropriate because categories are ordered, but differences cannot be found or are meaningless.
The population of ages at inauguration of all U.S. Presidents who had professions in the military is 62, 46, 68, 64, 57. Why does it not make sense to construct a histogram for this data set?
With a data set that is so small, the true nature of the distribution cannot be seen with a histogram.
Heights of adult males are normally distributed. If a large sample of heights of adult males is randomly selected and the heights are illustrated in a histogram, what is the shape of that histogram?
bell shaped
discrete or continuous? the numbers of murders in different cities in a certian year
discrete becuase the data can only take on on specific values
when a car is randomly selected it is found to have 3 wipers
discrete data set becuase there are a finite number of possible values
A _______ is a graph of each data value plotted as a point.
dotplot
what would be classified as categorical data?
hair color
determine which of the four levels of measurement (nomical, ordinal interval, ratio) is most appropriate for the data below ; states in a region
nominal
the ordinal level of measurement is the most appropriate because categories are ordered, but difference cannot be found or are meaningless hair colors
nominal
which level of measurement consists of categories only where data cannot be arranged in an ordering scheme
nominal
Fill in the blank. A(n) _______ distribution has a "bell" shape.
normal
Determine which of the four levels of measurement (nominal, ordinal, interval, ratio) is most appropriate. Voltage measurements of batteries: 1.5V, 3V, 4.5V, 6V, and 7.5V
ratio
Determine which of the four levels of measurement (nominal, ordinal, interval, ratio) is most appropriate. number of houses people own
ratio level of measurement is most appropriate becuase the data can be ordered
A _______ histogram has the same shape and horizontal scale as a histogram, but the vertical scale is marked with relative frequencies instead of actual frequencies.
relative frequency
A histogram aids in analyzing the _ of the data.
shape of the distribution
state whether the data described below are discrete or continuous and explain why. the circumference of peoples head
the data are continuous because the data can be taken on any value in an interval
determine whether the given value is statistic or parameter. a homeowner measured the voltage supplied to his come on 325 days ofa given year and the average (mean) value is 128.8 volts
the given value is a statistic for the year because the data collected represents a sample
determine which of the four levels of measurement (nominal, ordinal, interval, ratio) is most appropriate for the data below: internet speed levels of "fast," "medium," and "slow"
the ordinal level of measurement is the most appropriate because categories are ordered, but difference (obtained from subtraction) cannot be found or are meaningless
determine which of the four levels of measurement (nomical, ordinal interval, ratio) is most appropriate for the data below ; college rankings
the ordinal level of measurment is most appropriate because the data can be ordered but the differences cannot be found
A particular country has 50 total states. If the areas of all 50 states are added and the sum is divided by 50, the result is 192 comma 080 square kilometers. Determine whether this result is a statistic or a parameter.
the result is a parameter because it describes some characteristic of a population
determine whether the given value is statistic or parameter. a study was conducted of all 622 car owners in a certain country
the value is parameter becuase it is a numerical measurement describing some characteristic of a population
The bars in a histogram ___.
touch
If we have a large voluntary response sample consisting of weights of subjects who chose to respond to a survey posted on the Internet, can a graph help to overcome the deficiency of having a voluntary response sample?
No, a graph cannot help to overcome the deficiency. If the sample is a bad sample, there are no graphs or other techniques that can be used to salvage the data.
