Statistic

Q1: Easy
If p is the standard deviation of the six numbers 1, 5, 7, 8, 10, 11. Find the exact value of p.

• 3.46

Q2: Medium Easy

If the variance of the 5 numbers a, b, c, d, e is 88, then the variance of the 5 numbers 9a - 7, 9b - 7, 9c - 7, 9d - 7 and 9e - 7 is

• 7108

• 7120
• 7128
• 7224

• I only

• I and II only

• III only

• None of the above

Q4: Medium Hard

Let a1, b1 and c1 be the mean, range and standard deviation of a group of numbers {x1, x2, x3, x4, x5, x6, x7, x8} respectively while a2, b2 and c2 be the mean, range and standard deviation of a group of numbers {2 - x1, 2 - x2, 2 - x3, 2 - x4, 2 - x5, 2 - x6, 2 - x7, 2 - x8} respectively, which of the following must be true?

I. a1 = 2 - a2

II. b1 = b2

III. c1 = -c2

• I and II only

• I and III only

• II and III only

• I, II and III

Q5: Hard

• A

• B

• C

• D