Elementary Statistics 3.1
Each of the following three data sets represents the IQ scores of a random sample of adults. IQ scores are known to have a mean and median of 100. For each data set, compute the mean and median. (a) What is the mean of the sample of size 5? (b) What is the mean of sample size 12? (c) What is the mean of sample size 30? (d) What is the median of sample size 5? (e) What is the median of sample size 12? (f) What is the median of sample size 30?
(a) 101.6 (b) 103.1 (c) 100.7 (d) 102 (e) 103 (f) 101
A sample of 20 registered voters was surveyed in which the respondents were asked, "Do you think Chang, Johnson, Ohm, or Smith is most qualified to be a senator?" The results of the survey are shown in the table. (a) Determine the mode candidate. (b) Do you think it would be a good idea to rotate the candidate choices in the question? Why?
(a) Ohm (b)Yes to avoid response bias.
The following data represent the pulse rates (beats per minute) of nine students enrolled in a statistics course. Treat the nine students as a population. Complete parts (a) to (c). (a) Determine the population mean pulse. (b) Determine the sample mean pulse of the following two simple random samples of size 3. Sample 1: (Jeff comma Clarice comma Megan) Sample 2: (Kathy comma Clarice comma Perpectual) (c)Determine if the means of samples 1 and 2 overestimate, underestimate or are equal to the population mean
(a)The population mean pulse is approximately 80.2. (b) The mean pulse of sample 1 is approximately 81 bpm. The mean pulse of sample 2 is approximately 80 bpm. (c) The mean pulse rate of sample 1 overestimates the population mean. The mean pulse rate of sample 2 underestimates the population mean.
The following data represent the amount of time (in minutes) a random sample of eight students took to complete the online potion of an exam in a particular statistics course. Compute the mean, median, and mode time. 66.6, 78.1, 88.9, 110.1, 128.4, 101.3, 94.7, 121.8 Part A: Compute the mean exam time. Select the correct choice below and, if necessary, fill in the answer box to complete your choice.
A. The mean exam time is 98.74
Part B: Compute the median exam time. Select the correct choice below and, if necessary, fill in the answer box to complete your choice.
A. The median exam time is 98
Part C: Compute the mode exam time. Select the correct choice below and, if necessary, fill in the answer box to complete your choice.
B. The mode does not exist.
Find the population mean or sample mean as indicated. Sample: 21, 9, 4, 8, 8 Select the correct choice below and fill in the answer box to complete your choice
B. x̅=10
The accompanying data represent the weights (in grams) of a simple random sample of 50 candies. Determine the shape of the distribution of weights of the candies by drawing a frequency histogram. Find the mean and median. Which measure of central tendency better describes the weight of the candy? Choose the correct histogram below.
C
The U.S. Department of Housing and Urban Development (HUD) uses the median to report the average price of a home in the United States. Why do you think HUD uses the median?
C. HUD uses the median because the data are skewed right.
True or False: A data set will always have exactly one mode
False The mode of a variable is the most frequent observation of the variable that occurs in the data set. To compute the mode, tally the number of observations that occur for each data value. The data value that occurs most often is the mode. A set of data can have no mode, one mode, or more than one mode. If no observation occurs more than once, the data have no mode.
Which measure of central tendency better describes the weight of the candy?
The mean weight is x̅=.885 grams and the median weight is M+.885 grams. The distribution is symmetric so the mean is the better measure of central tendency.
The median for the given set of six ordered data values is 29.5. 5 12 27 __ 41 51 What is the missing value?
The missing value is 32
