STATISTICS AND PROBABILITY

Statistics :

Ø Statistics is a branch of applied mathematics concerned with collecting, organizing, and interpreting data.

Ø The data are represented by means of graphs.

Measures of Central Tendency :

Ø It is often convenient to have one number that represent the whole data.

Ø Such a number is called a Measures of Central Tendency.

Ø The Measures of Central Tendency usually will be near to the middle value of the data.

Ø For a given data there exist several types of central tendencies.

Ø The most common among them are

• Arithmetic Mean

• Median

• Mode

Overall View:

Probability :

Ø Probability means possibility.

Ø It is a branch of mathematics that deals with the occurrence of a random event.

Ø The value is expressed between zero and one.

PROBLEMS

1. Find the range of the following distribution.

2. The number of televisions sold in each day of a week are 13, 8, 4, 9, 7, 12, 10. Find its standard deviation.

3. The amount that the children have spent for purchasing some eatables in one day trip of a school are 5, 10, 15, 20, 25, 30, 35, 40, Using step deviation method, find the standard deviation of the amount they have spent.

4. Find the mean and variance of the first n natural numbers.

5. Express the sample space for rolling two dice using tree diagram.

6. Two dice are rolled. Find the probability that the sum of outcomes is ( I ) equal to 4 (ii) greater than 10 (iii) less than 13