18 . Below are my resting heart rates (in beats per minute ) for the month of January , according to my Fitbit. Dat Jan Jan Jan Jan Jan 10 11 12 13 Heart Jan Jan Jan Jan 14 15 Jan Jan 16 Jan Jan Jan Rate Jan Date 65 6 6 22 25 Jan Jan 27 Heart Jan 28 Jan Jan 30 31 68 69 Jan Jan Jan Jan Rate 6 8 Jan Jan 65 65 6 5 6 6 type / level of data is this ? b . W hat chart is used to graphically display this type of data ? Plot a chart for this data in Excel. d . What trends , if any , are visible in the heart rate data? 1 9 . Identify the follow ing a a . g errors . The sampling process is such that a specific group is excluded or under-represented in the sam ple either deliberately or inadvertently . The sampling process results in a statistical answer that is different from the population value but is im proved by increasing the sa e size c . The sampling process allows people to self-select. 20 . The following table lists the lengths of 180 prom o tional calls (nearest minute ) between the marketing department and potential custom ers for a lawn maintenance company. Marketing Call Times (minutes) Determine the population Use the system a tic formula to obtain a sample of size 20 . Start counting the skip for the sample with the first time and progress vertically . C . Determine the sample mean d . Is the sample mean the same as the population 1 ? Why orwhy not