**1. What Is Null Hypothesis?**

**Answer: **It is denote by H0 , is a statement about the value of a population parameter (such as mean), and it must contain the condition of equality and must be written as **=, ≤, or ≤.**

**2. What Is Linear Regression?**

**Answer: **It is one of the statistical techniques used in a Predictive analysis, in this technique will identify the strength of the impact that the independent variables show on deepened variables.

**polyfit( x,y2,1) %return 2.1667 -1.3333, i.e 2.1667x-1.3333**

**3. What is Regression?**

**Answer: ** Is an analysis in statistical modeling . It’s a statistical process for measuring the relationships among the variables; it determines the strength of the relationship between one variable and a series of other changing independent variables.

**4. what is the relationship between Data science and Statistics?**

**Answer: **Data Sciences include Mathematical Statistics along with Computer science and Applications. By combing aspects of statistics, visualization, applied mathematics, computer science Data Science is turning the vast amount of data into insights and knowledge.

**5. Explain about statistics branches?**

**Answer: ** There are 2 main branches:

**Descriptive statistics:** **descriptive statistics** summarizes the data from a sample using indexes such as mean or standard deviation.

**Inferential Statistics:** It draws the conclusions from data that are subject to random variation such as observation errors and sample variation.

**6****. What is Cluster Sampling?**

* Answer: It *is a technique used when it becomes difficult to study the target population spread across a wide area and simple random sampling cannot be applied. It is a probability sample where each sampling unit is a collection or cluster of elements.

### 7**. What is Systematic Sampling?**

* Answer: Systematic sampling* is a statistical technique where elements are selected from an ordered sampling frame. In this type of sampling, the list is progressed in a circular manner so once you reach the end of the list, it is progressed from the top again. The example for systematic sampling is equal probability method.