Stereo speakers are manufactured with a 0.15 probability of being defective. Five speakers are randomply selected. Let the random variable X be defined as the number of defective speakers. Find the expected value and standard deviation.

Determine the mean and variance of the random variable with the following probability mass function. f(x)=( 729divided by 91) (1 divided by 9) superscript x baseline comma x equals 1,2,3 round your answers to three decimal places (e.g. 98.765).

What is the range? can’t seem to find it out

How many and of which kind of roots does the equation f(x)=2x^4−9x^3+17x^2−16x+6 have?