Exam Preparation

Question 1

Median

Answer 1

• Put the numbers in order
• (n +1)/2
• find the number in that position

Question 2

Mode

Answer 2

• most frequent observation
• can be multi-modal or bi-modal

Question 3

Range

Answer 3

Xmax - Xmin

Question 4

MAD

Answer 4

Tip: create table

Question 5

Variance

Answer 5

Question 6

Standard Deviation

Answer 6

(if it is a sample = n-1)

Question 7

Coefficent of Variation

Answer 7

(Standard Deviation x 100)/Mean

Question 8

When will the mean and the median be equal?

Answer 8

If the data are symmetrically distributed

Question 9

Grouping Data

Answer 9

1. Find smallest and biggest number
2. Decide lower and upper class limit
3. Find class width: (largest-smallest)/log2(n)
4. Number of classes: (upper class-ower class)/width
5. Create a table: class | class interval | lower boundary | upper boundary |

Question 10

Proprieties of Probability

Answer 10

• The probs of any event occurring: between 0 and 1
• If an even has a prob of 0 –> it will never occur
• If an event has a prob of 1 –> it will certainly occur
• The sum of all probs of all possible outcomes occurring = 1

Question 11

Types of Event

Answer 11

• Indipendent
• Mutually Exclusive
• Dependent or Conditional

Question 12

Simple Index

Answer 12

(P_n / P_o ) x 100

Question 13

Compound Growth Inverse Formulas

Answer 13

Question 14

Compound for Depreciation

Answer 14

F_t = F₀ (1-r)^t

Question 15

General Repayment Loan Formula

Answer 15

A =L/B_tr

L = A*B_tr

_{(use table B, for t and r )}

Question 16

Weighted Price Index

Answer 16

Σw_i(p_in/p_io)/Σw_i

Question 17

Probability Formulas

Answer 17

Indipendent Events = P(A) X P(B)

Mutually Exclusive Events = P(A) + P(B)

Non-mutually Exclusive Events = P(A) + P(B) - [P(A)XP(B)]