TRUE (T)-FALSE (F) 1.
Simple random sampling will ensure a representative sample.
The whiskers on a box plot extend to the smallest and largest data pieces.
Variance can never be smaller than its standard deviation.
If a random variable, X, has the values , 3, 4, 5 or 6 andthen= 0.
Expected value of the probability distribution in problem 4 is 4.
For P(A) = 0.
84, P(B) = 0.
76, and P(A or B) = 0.
90, the P(A and B) = 0.
Given that P(A and B) = 0.
45 and P(A) = 0.
9 then P(B given A) = 0.
Significance level measures how frequently the conclusion will be correct over the long haul.
Confidence level is the proportion of times that an estimating procedure will be in error.
Standard deviation for a binomial distribution with n = 50 and p = 0.
2 will be about 2.
A binomial distribution with n = 90 and p = 0.
4 will have mean equal to 40.
Mutually exclusive and independent are synonymous statistical terms.
Multi-outcome experiments cannot be studied using the binomial distribution.
The probability that two carriers of cystic fibrosis will have an afflicted child in any given birth is ¼.
If two carriers plan to have 5 children, the probability that at least 1 of the 5 will be afflicted with CF is approximately 0.
Some sources claim that one out of two marriages fail.
Assuming that figure is accurate, given 20 randomly drawn newly married couples, the probability that exactly half of these marriages will fail is approximately 0.
COMPLETION Use the given population data of employee weights to calculate the statistics that follow.
144 192 145 153 185 154 163 198 162 194 172 168 174 164 146 156 263 169 150 168 156 152 171 168 146 157 173 1.
1st Quartile 2.
3rd Quartile 4.
Interquartile Range 5.
90th percentile 6.
Standard Deviation 11.
Coefficient of Variation 12.
Weight to which upper whisker of a box plot would extend 13.
Calculate the percentage given by 1 – 1/k^2 if k = 3.
Form the interval (? +/- 3.
What % of the weights fall into this interval? III.
P(A) = P(B) 2.
Mean, Median, Mode 5.
Confidence Level g.
Population Measure 8.
Significance Level h.
P(A and B) = P(A) x P(B) 9.
Descriptive Statistics i.
Entire Group 10.
Inferential Statistics j.
All Possible Outcomes 11.
Central Tendency k.
Sample Measure 12.
Statistics Inferring Parameters 13.
Chart Of Class Intervals 14.
Probability Range n.
0 = P(E) = 1 16.
Frequency Distribution p.
Part Of An Entire Group 17.
Chebysheff’s Theorem q.
Sample Space r.
Population Characteristic 19.
Equally Likely Events s.
Range, Variance, Standard Deviation 20.
Independent Events t.
Extracting Information IV.
MULTIPLE CHOICE 1.
Which of the following is not the goal of descriptive statistics? Summarizing data Displaying aspects of the collected data Reporting numerical findings Estimating characteristics of the population None of these 2.
Which of the following statements is not true? One form of descriptive statistics uses graphical techniques One form of descriptive statistics uses numerical techniques In the language of statistics, population refers to a group of people Statistical inference is used to draw conclusions or inferences about characteristics of populations based on sample data None of these 3.
The most appropriate type of chart for determining the number of observations at or below a specific value is: a histogram a pie chart a time-series chart a cumulative frequency ogive none of these 4.
The total area of the six bars in a relative frequency histogram for which the width of each bar is five units is: 6 5 11 1 none of these 5.
Which of the following statements about pie charts is false? Pie charts are graphical representations of the relative frequency distribution Pie charts are usually used to display the relative sizes of categories for interval data.
Pie charts always have the shape of a circle Area of each slice of a pie chart is the proportion of the corresponding category of the frequency distribution of a categorical variable None of these 6.
Which of the following statements is false? All calculations are permitted on interval data All calculations are permitted on nominal data The most important aspect of ordinal data is the order of the data values The only permissible calculations on ordinal data are ones involving a ranking process None of these 7.
Which of the following statements is false? A frequency distribution counts the number of observations that fall into each of a series on intervals, called classes that cover the complete range of observations.
The intervals in a frequency distribution may overlap to ensure that each observation is assigned to an interval Although the frequency distribution provides information about how the numbers in the data set are distributed, the information is more easily understood and imparted by drawing a histogram The number of class intervals we select in a frequency distribution depends entirely on the number of observations in the data set.
None of these 8.
The relative frequency of a class is computed by dividing the frequency of the class by the number of classes dividing the frequency of the class by the class width dividing the frequency of the class by the total number of observations in a set subtracting the lower limit of the class from the upper limit and multiplying difference by the number of classes none of these 9.
A modal class is the class that includes the largest number of observations the smallest number of observations the largest observation in the data set the smallest observation in the data set none of these 10.
The two graphical techniques usually used to present nominal data are bar chart and histogram pie chart and ogive bar chart and pie chart histogram and ogive none of these 11.
The most important and common graphical presentation of interval data is a bar chart histogram pie chart cumulative frequency distribution none of these 12.
The relationship between two interval variables is graphically displayed by a scatter diagram histogram bar chart pie chart none of these 13.
The effect of making the slope of a line graph appear steeper can be created by: Stretching the vertical axis.
Shrinking the horizontal axis.
Stretching the horizontal axis.
Both a and b None of these 14.
Possible methods of creating distorted impressions with bar charts include: Stretching the vertical axis.
Shrinking the horizontal axis Constructing the bars so that their widths are proportional to their heights.
All of the above None of these 15.
Which of the following statements about the arithmetic mean is not always correct? The sum of the deviations from the mean is zero Half of the observations are on either side of the mean The mean is a measure of the middle (center) of a distribution The value of the mean times the number of observations equals the sum of all of the observations.
None of these 16.
In a histogram, the proportion of the total area, which must be to the left of the median, is: exactly 0.
50 less than 0.
50 if the distribution is skewed to the left more than 0.
50 if the distribution is skewed to the right between 0.
25 and 0.
60 if the distribution is symmetric and unimodal none of these 17.
If two data sets have the same range: the distances from the smallest to largest observations in both sets will be the same the smallest and largest observations are the same in both sets both sets will have the same mean both sets will have the same interquartile range none of these 18.
A population of 20 exams has a standard deviation of 3.
The sum of the squared deviations from the mean is: 9 60 171 180 none of these 19.
Which measure of central location is meaningful when the data are nominal? The arithmetic mean The geometric mean The median The mode None of these 20.
Chebyshev’s Theorem states that the percentage of measurements in a data set that fall within 4 standard deviations of their mean is: 93.
75% at least 93.
8% at least 91.
8% none of these 21.
The Empirical Rule states that the percentage of measurements in a data set (provided that the data set has a bell-shaped distribution) that falls within three standard deviations of their mean is: 68% 75% 95% 99% none of these 22.
Since the population is always larger than the sample, the population mean: is always larger than the sample mean is always smaller than the sample mean is always larger than or equal to the sample mean is always smaller than or equal to the sample mean none of these 23.
Which of the following summary measures is affected least by outliers? The median The variance The range The mean None of these 24.
Which of the following summary measures cannot be easily approximated from a box-and- whisker plot? The range The interquartile range The second quartile The standard deviation None of these 25.
The average score for a class of 30 students was 75.
The 20 male students in the class averaged 70.
The 10 female students in the class averaged: 70 75 80 85 none of these 26.
Which of the following is not a measure of variability? The range The variance The interquartile range The standard deviation None of these 27.
The length of the box in the box-and-whisker plot portrays the: median range interquartile range first and third quartiles none of these 28.
Which of the following statements is true for the following data values: 7, 5, 6, 3, 7, 8, and 12? The mean, median and mode are all equal Only the mode and median are equal Only the mean and mode are equal Only the median and mean are equal None of these 29.
When every possible sample with the same number of observations is not equally likely to be chosen, the selected sample is called: Biased Stratified Cluster Random None of these 30.
Which of the following statements is correct in questionnaire design? The questionnaire and questions should be kept as short as possible.
A mixture of dichotomous, multiple-choice, and open-ended questions may be used.
Leading questions must be avoided.
All of the above are correct statements None of these