In 1990, the mean duration of long-distance telephone calls originating in one town was 7.2 minutes. A long-distance telephone company wants to perform a hypothesis test to determine whether the mean duration of long-distance phone calls has changed from the 1990 mean of 7.2 minutes. H0: μ < 7.2 minutes Ha: μ > 7.2 minutes H0: μ = 7.2 minutes Ha: μ ≠ 7.2 minutes H0: μ = 7.2 minutes Ha: μ ≤ 7.2 minutes H0: μ ≠ 7.2 minutes Ha: μ = 7.2 minutes

Show algebraically that f and g are inverse functions f(x)=x^2/-6; g(x)=square root of 2x+12

Asmall (but heavy) particle placed in a glass of water will follow a zigzag motion because the particle will bounce off of the water molecules it meets. this is called brownian motion. a physicist simulates this on a computer, by varying the distance a particle can travel (called the mean free length), on average, before it collides with a water molecule and assigning the change in motion to be one of 8 directions, each with a similar probability. by running the simulated particle (with the same mean free length) many times she determines that it should take 15 seconds, on average, for the particle to fall to the bottom, with a standard deviation of 1.5 seconds. next she lets a real particle fall through a glass of water and finds that it took 18 seconds. what does she conclude, and why?

Adiverr from the university of florida women’s swimming and diving team is competing in the ncaa zone b championships