Math topic中文

Standard deviation calc

calculation of the standard deviation for a set of data (grouped and ungrouped)

Practice questions

  1. 1A survey was carried out to find out the number of emails received in a week by each of a group of students. The table b…
  2. 2The cumulative frequency curve shows the marks obtained by the 120 students in a recent Mathematics Test. The maximum ma…
  3. 3The marks of a group of 19 students in a test were recorded, as the marks are shown in the stem and leaf diagram. The mo…
  4. 4The following stem-and-leaf diagram shows the marks obtained by 20 pupils in a class test that has a total mark of 50. S…
  5. 5The masses of 20 bags, in kg, are measured. The results are shown on the stem-and-leaf diagram. Find the mean mass of th…
  6. 6The stem and leaf diagram below shows the marks obtained by 30 students in a Science test marked out of 80 marks. Find t…
  7. 7The waiting time, t in minutes, for 40 customers at two phone service shops, Shop A and Shop B, are as follows. Calculat…
  8. 8The temperatures of eighteen girls in a class on a particular day are shown in the stem-and-leaf diagram. (Stem-and-leaf…
  9. 9Mr Tan designed two computer models X and Y. Both have the same manufacturing cost. Mr Tan engaged his existing client M…
  10. 10The table below shows the amount of time spent playing online games by a group of children in one particular week. Calcu…
  11. 11The masses of 20 bags, in kg, are measured. The results are shown on the stem-and-leaf diagram. Find the mean mass of th…
  12. 12The table shows the height, h cm, of 60 plants. Calculate an estimate of the standard deviation of the height of the pla…
  13. 13The table shows the height of 100 men who were at the health center. Find the estimated mean height of the men. Answer _…
  14. 14In an experiment with 16 observations on x, the following results were obtained: ∑x=182\sum x = 182, ∑x2=3548\sum x^2 = 3548 One o…
  15. 153.8 is the mean of 5 positive numbers a, b, c, d and e. The sum of their squares is 360. Each of the numbers is now mult…
  16. 16The frequency table shows the reaction time, t seconds, for a chemical to change the colour of the litmus paper in 100 l…
  17. 17A researcher wants to conduct a study to find out if there is a correlation between the analytical skills of adults with…
  18. 18The table below shows the number of books read by 50 students in Class A in semester 1. Calculate an estimate for the me…
  19. 19A group of students recorded the volume of water using a measuring cylinder in an experiment. The mean volume of water r…
  20. 20The mean of ten different numbers is 11.8. Write down a number which will generate a mean of 12, when added to these ten…
  21. 2120 female shoppers went to buy their groceries. The amount of time (in minutes) each female shopper spent is shown in th…
  22. 22Given that x1,x2,x3,…,x10x_1, x_2, x_3, \dots, x_{10} are 10 unique numbers whose mean, xˉ\bar{x}, is 11.8 and standard deviation is…
  23. 23The table below summarises the times taken by female participants to complete a 10 km race. Given that the estimated mea…
  24. 24A group of students was asked to complete a class test. The time taken to complete the test was represented as shown in…
  25. 25The masses of 40 oranges were measured. The cumulative frequency curve below shows the distribution of the masses. Use t…
  26. 26A group of 50 patients had their blood pressure taken. The results are shown in the table below. State the median class…
  27. 27The distances travelled per litre of petrol of 50 cars manufactured in Factory X are shown in the table below. Calculate…
  28. 28The histogram below shows the distribution of the scores of the participants from Potong Pasir Secondary School in a cur…
  29. 29The table shows the distribution of the weights of 40 students. Find the value of a. Answer a = ... Calculate an estimat…
  30. 30The number of customers, cc, served in a day at a counter for 40 days are given below. Calculate the mean number of cus…