Welcome back to our usual blog of Excel functions from A to Z. Today we look at the CONFIDENCE function.
The CONFIDENCE function
You need more CONFIDENCE in your Excel files? This function returns the confidence interval for a population mean, using the theory associated with the normal distribution.
To explain: the confidence interval is a range of values around a sample mean, X, located at the center of this range, In other words the range is X ± CONFIDENCE. As an example, and X it is the sample mean of the delivery times of products ordered by mail, x ± CONFIDENCE is a range of population means.
For any population mean, μ0, within this range, the probability of obtaining a sample mean further away from it μ0 that X is greater than the required significance level, alfa; for any population mean, μ0, not in this range, the probability of obtaining a sample mean further away from it μ0 that X is less than this level, alfa. In other words, suppose we use X, a standard deviation standard_dev, Y Size construir una prueba de dos colas al nivel de significancia alfa de la hipótesis de que la media de la población es μ0. Entonces no rechazaremos esa hipótesis si μ0 está en el intervalo de confianza y rechazará esa hipótesis si μ0 no está en el intervalo de confianza. El intervalo de confianza no nos posibilita inferir que exista probabilidad 1 – alfa que nuestro próximo paquete llevará un tiempo de entrega que se encuentra en el intervalo de confianza.
