Si el gerente de control de calidad desea estimar la media de vida de lámparas con 20 horas, con un nivel de confianza del 95% y se supone un error de 10%. ¿Cuál es el tamaño de la muestra?

Enter the missing numbers in the boxes to complete the table of equivalent ratios of lengths to widths. ? 18 8 ? 10 30 12 ?

What is the name used to describe a graph where for some value of x, there exists 2 or more different values of y?

The number if marbles of different colors stored in a hat is listed below: 4 red marbles 10 green marbles 7 blue marbles. without looking in the hat, dan takes out a marble at random. he replaces the marble and then takes out another marble from the hat. what is the probability that dan takes out a blue marble in both draws?