# How do you find sample size without standard deviation?

## How do you find sample size without standard deviation?

How to Find a Sample Size Given a Confidence Level and Width (unknown population standard deviation)

1. za/2: Divide the confidence level by two, and look that area up in the z-table: .95 / 2 = 0.475.
2. E (margin of error): Divide the given width by 2. 6% / 2.
3. : use the given percentage. 41% = 0.41.
4. : subtract. from 1.

## How do you calculate sample size without population?

For sample size calculation of unknown population size, you can use the following formula: n= z2. [p*q]/d2), which is used to calculate the sample size of a qualitative variable in prevalence or cross-sectional studies.

How do you determine the sample size for an unknown population?

q =1-p .. This is an online calculator that helps you to calculate the needed sample size. All you need to know first are the Confidence Level and Confidence Interval. z= Z score….Here are the z-scores for the most common confidence levels:

1. 90% – Z Score = 1.645.
2. 95% – Z Score = 1.96.
3. 99% – Z Score = 2.576.

### What is Kish grid method of sampling?

The Kish grid or Kish selection grid is a method for selecting members within a household to be interviewed. It uses a pre-assigned table of random numbers to find the person to be interviewed. It was developed by statistician Leslie Kish in 1949. It is a technique widely used in survey research.

### What is the formula for finding a sample size?

Sample Size Formula. The Sample Size Calculator uses the following formulas: 1. n = z 2 * p * (1 – p) / e 2. 2. n (with finite population correction) = [z 2 * p * (1 – p) / e 2] / [1 + (z 2 * p * (1 – p) / (e 2 * N))] Where: n is the sample size, z is the z-score associated with a level of confidence, p is the sample proportion, expressed as a

How to calculate standard deviation without a data set?

– You formulate a hypothesis ( make a guess) of what your numbers ( data set) probably will be . – You scrounge around and find a data set from a hypothesis. – You calculate the SD for those numbers. – You figure out how your professor likes the SD to look. – You report that as an estimated SD.

## How to determine the correct survey sample size?

– (1) Margin of error — the level of precision a researcher is required to specify. – (2) Confidence level — the amount of uncertainty associated with an estimate (also known as margin of error around the estimate.) The table above provides formulas for the components of – 3) Population Size — “How many total people fit your demographic?

## How to determine sample size, determining sample size?

Know your population size. Population size refers to the total number of people within your demographic.

• Determine your margin of error. Margin of error,also referred to as “confidence interval,” refers to the amount of error you wish to allow in your results.
• Set your confidence level.
• Specify your standard of deviation.
• Find your Z-score.