The National Institute of Standards and Technology (NIST) supplies a 'standard liquid' whose electrical conductivity is supposed to be exactly 5. A certain shipment of the liquid sat outside in warm weather for several extra hours in a truck trapped on an interstate because of a rock slide. Is there reason to think that the true conductivity of this shipment has decreased? To find out, NIST measures the conductivity six times, using an SRS of samples from the affected shipment. The sample's mean conductivity is 4.78. Past study indicates that the population of all possible measurements of conductivity has standard deviation σ = 0.2. Is the sample outcome statistically significant at the α = 0.03 level? A) - 2.69.
B) Yes, we have proven that the shipment's conductivity is too low.
C) Yes.
D) No.