Confidence Intervals for the Mean - Sigma Unknown Case

This video covers topics in confidence intervals for the mean involving population mean, mu with standard deviation (sigma is not given in the question) Topics discussed include:

- Point estimate and interval estimate for the mean
- Confidence levels (90%, 95%, 98%, and 99%)
- z-table vs t-table: when to use each one
- how to read and use a t table (student's t-distribution table)
- Degrees of freedom and critical value
- Interpreting the confidence interval

[navjeetkaur]

With this video, I understand that when the population standard deviation is known then we use the z table. When the population standard deviation is unknown then we use t -table. We check whether the population is normally distributed or n is greater than/equal to 30. We calculate the margin of error using the formula provided. For finding critical value, we use degree of freedom in case of t table i.e. n-1. We use level of confidence provided in the question to find value in the table. We interpret the result by statement - we are __% sure and using the statement from question.

[SohajpreetKaurRai]

I understand interval as the range and confidence level as in percentage out of which 95% is most commonly used, rest of 5% means don’t have ‘u’ i.e., confidence interval. If sigma is known, we use z table and if unknown sigma or only s is given then use t table.