4. The lowest and the highest data value of a data set are 12 and 28 respectively, then the approximate standard deviation is:

The instructor takes a random sample of size from the population data and obtains the following sample data:                   x 405 385 495 385 555 470   8 The sample standard deviation is, a 69.17     b 66.51     c 63.14     d 61.49

The length of time it takes for a worker to perform certain task (in minutes) was recorded for 10 workers. The resulting data values were the following: 5, 3, 11, 7, 6, 9, 4, 8, 7, 10 Find the mean, median, mode, range, variance and standard deviation. In the answers for the mean, variance, and standard deviation leave one digit after decimal point. a. Mean = d. Range = b. Median = e. Variance = c. Mode = f. Standard deviation =

Dianne has a choice of two routes to drive to work. She timed her journey along each route on several occasions and the times in minutes are given below:Town route: 15, 16, 20, 28, 21Country route: 19, 21, 20, 22, 18(i) Calculate the mean and standard deviation (to one d. p.) of each set of journey times.(ii) Which route would you recommend? Give a reason.

Find the standard deviation.. Round to one more place than the data 7,19,20,8,17, 14, 8, 20, 12 O A. 5.1 O B. 1.7 O C. 5.4 O D. 5.7