Z table and Normality

Normal Distribution:

The normal curve is continuous, symmetrical, unimodal, have a bell-shaped form and mean, median and mode is equal. The distribution contains an infinite number of cases. Normal distribution differs by mean and standard deviation.

Z score:

Z score tells us how many standard deviations a data value is above or below the mean for a specific distribution of values. If the standard deviation is zero, then the data value is the same as the mean.

Standard Normal curve:

A normal curve with mean zero and standard deviation 1 is called a standard normal curve.

Central limit theorem:

As the sample size n increases without limit, the sample mean is considered instead of the population mean.

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Frequency Distribution and Data Presentation

A frequency distribution is a table that displays the frequency of various outcomes in a sample. Each entry in the table contains the frequency or count of the occurrences of values within a particular group or interval, and in this way, the table summarizes the distribution of values in the sample. Organizing Data. 1.Arrange data into an array 2. Decide on the number of classes( k) 3. Calculate the class interval 4. Prepare a tally sheet There are two types of Frequency: Categorical frequency distribution. Grouped frequency distribution. Categorical Frequency Distributions The categorical frequency distribution is used for data that can be placed in specific categories or represent values of a qualitative variable. Grouped Frequency Distributions: When the data are numerical and their range is large, the data must be grouped into classes that are more than one unit in length. Histogram The histogram is an accurate graphical representati...

Hypothesis Testing

Hypothesis refers means an educated guess or an assumption that can be tested. Forms of hypothesis: 1. HA- Research hypothesis 2. HO- Null hypothesis HA: Research hypothesis: The research hypothesis is also known as an alternate hypothesis. HA is a statement on which a statistical hypothesis test is set up. HO- Null hypothesis: Null hypothesis is also known as no difference or no relationship, this is used to facilitate testing of research hypothesis Types of hypothesis: · One-tailed- Directional HA: p>0 HO: p<0 · Two-tailed- non-directional HA: p not equal to zero Types of Error: Type 1 Error – Rejection of a true Null hypothesis. Type 2 Error – It may have a false negative finding. Type 1 error is donated by Alpha. Level of significant can reduce...

Population and Sample

A Population comprises of all elements showing the parameters of an individual or objects. Whereas, a Sample is a sub-set of a population showing statistics.

Priyanka Thakur

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