Confidence Intervals for the Difference between Means from Two Independent Samples (Variance Known)

**CONFIDENCE INTERVALS FOR THE DIFFERENCE BETWEEN MEANS FROM TWO
INDEPENDENT SAMPLES (VARIANCES KNOWN)**

When the population variances are known, we use the
*Z* statistic defined in the previous
section, namely

*Z *has exactly a standard normal distribution when the
observations in both samples* *are
normally distributed. Also, based on the central limit theorem, *Z* is approximately normal if conditions
for the central limit theorem are satisfied for each population being sampled.
For a 95% confidence interval we know that *P*(–*C* ≤ *Z* ≤ *C*) = 0.95
if C = 1.96.

For other confidence levels, we just change the constant *C* to 1.645 for 90% or 2.575 for 99%.
Display 8.4 pro-vides the formula for the 95% confidence interval for the
difference between two population means, assuming common known population
variance.

Related Topics

Contact Us,
Privacy Policy,
Terms and Compliant,
DMCA Policy and Compliant

TH 2019 - 2025 pharmacy180.com; Developed by Therithal info.