# simple random sampling

1. ### How to estimate population statistics for each category ?

I have data from a simple random sample having n elements which I’m using to estimate my overall population statistics (mean). My population can be divided into k categories, and I know the composition of my overall population in terms of these categories. As part of my study, I want to estimate...
2. ### Comparing means with known standard deviation known

1). The average number of pages for a simple random sample of 20 physics textbooks is 435. The average number of pages for a simple random sample of 25 mathematics textbooks is 404. Assume that all page length for each types of textbooks is normally distributed. The standard deviation of page...
3. ### Need a help for sample size calculation

I have a database of 1500 records and I am are going to use the database for future use, if the inaccuracy of the data elements (eg. Date of birth of each record) is less than 5% (or accuracy is more than 95%). I am planning to get a simple random sample from the database and check with the...