Mark wants to know how many families in his neighborhood plan to attend the neighborhood party. he puts all 80 of the neighborhood addresses in a hat and draws a random sample of 20 addresses. he then asks those families if they plan to attend the party. he finds that 20% of the families plan to attend the party. he claims that 20% of the neighborhood families would be expected to attend the party. is this a valid inference?

a. no, this is not a valid inference because he asked only 20 families
b. no, this is not a valid inference because he did not take a random sample of the neighborhood
c. yes, this is a valid inference because he took a random sample of the neighborhood
d. yes, this is a valid inference because the 29 families speak for the whole neighborhood

i know that is not a or b. : )

Name and describe the three most important measures of central tendency. choose the correct answer below. a. the mean, sample size, and mode are the most important measures of central tendency. the mean of a data set is the sum of the observations divided by the middle value in its ordered list. the sample size of a data set is the number of observations. the mode of a data set is its highest value in its ordered list. b. the sample size, median, and mode are the most important measures of central tendency. the sample size of a data set is the difference between the highest value and lowest value in its ordered list. the median of a data set is its most frequently occurring value. the mode of a data set is sum of the observations divided by the number of observations. c. the mean, median, and mode are the most important measures of central tendency. the mean of a data set is the product of the observations divided by the number of observations. the median of a data set is the lowest value in its ordered list. the mode of a data set is its least frequently occurring value. d. the mean, median, and mode are the most important measures of central tendency. the mean of a data set is its arithmetic average. the median of a data set is the middle value in its ordered list. the mode of a data set is its most frequently occurring value.