60 randomly selected students were asked how many siblings were in their family. let x = the number of pairs of siblings in the student's family. the results are as follows: siblings1 2 3 4 5 6 7 frequency 13 22 15 6 3 0 1 round your answers to two decimal places. the mean is: the median is: the sample standard deviation is: the first quartile is: the third quartile is: what percent of the respondents have had less than 3 siblings? % 20% of all respondents have had at most how many siblings?