question archive The following "less than" cumulative frequency distribution shows the average waiting times at a bank, for a sample of 60 customers
The following "less than" cumulative frequency distribution shows the average waiting times at a bank, for a sample of 60 customers
Subject:StatisticsPrice: Bought3
The following "less than" cumulative frequency distribution shows the average waiting times at a bank, for a sample of 60 customers. Waiting times (minutes) Number of customers <10 8 <20 26 <30 40 <50 54 <70 60 (i) State the variable of interest. Indicate whether the variable is quantitative discrete, quantitative continuous or qualitative. (2 marks) (ii) Draw a "less than" cumulative frequency polygon. Use the graph to estimate (4 marks) (1) the median and interpret the result. (2 marks) (2) the lower quartile and upper quartile. Hence, calculate the quartile deviation. (3 marks) (3) the percentage of the customers whose average waiting times are exceeded by 40 minutes. (2 marks) (iii) Calculate the mean and standard deviation of waiting times for the customers. (7 marks) (b) The following data shows the marks obtained by all the 13 students in a Statistics test: 46 72 80 92 88 37 51 93 56 60 76 56 96 Construct a box- and- whisker plot and comment on the skewness of the distribution.
