Notes for Homework 9, due April 10

Notes on mean, median and mode

Notes on the five number summary and outliers

Notes on z-scores, normal distribution and proportions

Notes for Homework 8, due March 28

Notes on determinants

A 2x2 matrix is an array of four numbers put in two rows and two columns, such as

| a c |
| b d |

The determinant of this matrix is ad - bc, the product of the main diagonal minus the product of the opposite diagonal. If you use Kramer's rule to solve a pair of simultaneous equations, you will need to know how to calculate determinants.

For example, let's consider the following set of equations.

3x - 2y = 7
2x + 4y = 12

As an augmented matrix , these equations become

|  3  -2  : 7 |
|  2   4  : 12|

Matrix_1 is

| 3 -2 |
| 2  4 |

The determinant is 3(4) - 2(-2) = 12 - -4 = 16
 

Matrix_x is

| 7 -2 |
| 12  4 |

The determinant is 7(4) - 12(-2) = 28 - -24 = 52
  Matrix_y is

| 3  7  |
| 2 12 |

The determinant is 3(12) - 2(7) = 36 - 14 = 22

From here, Kramer's rule then has x = 52/16 = 13/4 or 3 1/4. The value for y = 22/16 = 11/8 = 1 3/8
 
  Notes on solving simultaneous equations
 

Notes for Homework 7, due March 20

Notes for contingency tables

Notes for coin problems

Notes for slope, point-slope and slope-intercept
 

Notes for Homework 6, due March 13

Notes on rates other than percent

Notes on set theory and Venn diagrams
 

Link to biographies of Archimedes, Newton, Euler and Gauss.

Link to the biographies