Dentistry

?Assignment Topic: – Inferential Statistics

?Course Title: – Statistics

?Course Code: – SGS116

?Lecture Group: – A

?Submitted to: – ?Dr. Ahmed Refaat

?Prepared by: Mohamed emad hamday – 180013

?

Definition

Statistics have two main branches, first one Descriptive statistics and second one is Inferential statistics.

Inferential statistics have a lot of definitions. Inferential statistics is the way to use simple of group (population) to make inferences about that group (population).

Also in another way it means that we use a little part of people to make prediction about the whole people itself.

Also it can define as a decision take from simple of the all data

1

Main types of Inferential statistics

1. T-test

2. ANOVA (Analysis of variance)

3. Regression

1-T-test

Used to:Used to:

1) Compare between two individuals (means) to know if they came from same group or no.

2) It makes you know how significant the difference between two variables is.

Also, it is called (Student’s T-test).

The types of t-test are

1-One-sample t-test is used to decide if a sample of observations could have been shown up by a process with a specific mean or no.

There two types:-

I. The alternative hypothesis suppose that some difference exists between the true mean (?) and the comparison value (m0)

II. The null hypothesis suppose that no difference exists. The aim of the one sample t-test is to acknowledge if the null hypothesis should be rejected, given the sample data.

There are 3 forms:-

If the aim is to measure any difference without lock to direction a two-tailed hypothesis is used.

If the direction of the comparison between the sample mean and the comparison value are important, either an upper-tailed or lower-tailed hypothesis is used

• H1: ? ? m0 (two-tailed)

• H1: ? > m0 (upper-tailed)

•

2

H1: ? 0 (upper-tailed)

• H1: ?d