Statistics

Problem Statement

Definition

Class:

AverageAverage

Method:

average

Parameters:

int[]

Returns:

double

Method signature:

double average(int[] numList)

(be sure your method is public)

Notes

• The returned value must have an absolute or relative error less than 1e-9.

Constraints

• numList will contain between 1 and 8 elements, inclusive.
• All elements of numList will be between -1000 and 1000, inclusive.
• All elements of numList will be distinct.

Examples

1. {1,2,3}

   Returns: 2.0

   The non-empty subsets of numList are: {1}, {2}, {3}, {1,2}, {1,3}, {2,3}, and {1,2,3}, whose respective averages are: 1, 2, 3, 1.5, 2, 2.5, and 2. The average of the averages is 2.

2. {42}

   Returns: 42.0

   There is only one non-empty subset to consider.

3. {3,1,4,15,9}

   Returns: 6.4

4. {977}

   Returns: 977.0

5. {178}

   Returns: 178.0

6. {-315}

   Returns: -315.0

7. {437,-372}

   Returns: 32.5

8. {-262,-676}

   Returns: -469.0

9. {-114,-401}

   Returns: -257.5

10. {90,-200,-223}

    Returns: -111.0

11. {-213,-955,153}

    Returns: -338.3333333333333

12. {104,763,569}

    Returns: 478.6666666666667

13. {-735,-967,704,473}

    Returns: -131.25

14. {-432,-126,-773,-684}

    Returns: -503.75

15. {-757,642,21,761}

    Returns: 166.75

16. {-22,157,-580,-984,658}

    Returns: -154.2

17. {766,-358,-215,-156,-343}

    Returns: -61.2

18. {-727,725,755,23,974}

    Returns: 350.0

19. {463,211,-276,-117,-425,341}

    Returns: 32.833333333333336

20. {-790,-79,153,572,-826,-717}

    Returns: -281.1666666666667

21. {-728,-933,-654,973,-622,-824}

    Returns: -464.6666666666667

22. {533,214,553,-812,555,-448,265}

    Returns: 122.85714285714286

23. {-994,-214,-587,828,571,-596,-622}

    Returns: -230.57142857142858

24. {961,-862,-36,191,-38,136,855}

    Returns: 172.42857142857142

25. {-353,-586,907,237,-688,-736,302,-537}

    Returns: -181.75

26. {114,710,-205,-659,-871,900,-112,611}

    Returns: 61.0

27. {-392,-348,230,742,-345,380,-631,773}

    Returns: 51.125

28. {0}

    Returns: 0.0

29. {-1000,-999,-998,-997,997,998,999,1000}

    Returns: 0.0

30. {3, 1, 4, 15, 9 }

    Returns: 6.4

31. {0 }

    Returns: 0.0

32. {1000, 12, 124, 54, 457, 45, 454 }

    Returns: 306.57142857142856

33. {1, 2, 3 }

    Returns: 2.0

34. {1, 15, 9, 3, 4, 1000, -1000, -999 }

    Returns: -120.875

35. {2, 3, 9 }

    Returns: 4.666666666666667

36. {-1, 1, 2, 3, 4, -5, -1000, 0 }

    Returns: -124.5

37. {42, 14, 15, 99, 0 }

    Returns: 34.0

38. {0, 2, -1 }

    Returns: 0.3333333333333333

39. {91, -100, 4, 10, -45, 67, -89, -22 }

    Returns: -10.5

40. {1, 2, 3, 4, 9, 13, 15 }

    Returns: 6.714285714285714

41. {467, 456, 234, 879, 657, 567, 89, -324 }

    Returns: 378.125