1. you are in charge of monitoring the pressure of a compressed air tank in a processing plant. after repeating the pressure measurement a large number of times, you found that the pressure values have gaussian distribution with a mean value of 69 psi and a standard deviation of 10 psi. if it is important that the pressure stays below 82 psi, what is the probability (in percent) that the pressure will exceed this value?

the answer is 3.1 his answer is wrong mines is right

speed of light in vacuum is 300,000 km/s

speed of light in other mediums is given by the expression v = c/n, where c is the speed of light in vacuum and n is the refractive index of medium.

for the first medium v = 200,000 km/s

  so, refractive index of medium = 300000/200000 = 1.5

    1.5 refractive index is usually for glass. so first medium is glass.

for the second medium v = 250,00 km/s

so, refractive index of medium = 300000/250000 = 1.2

    1.2 refractive index is usually for water. so second medium is water.

for the third medium v = 0 km/s

so, refractive index of medium = 300000/0 = ∞

    ∞ refractive index is usually for opaque mediums. so third medium is opaque medium.