For questions 15-18 write a linear equation given the point and slope or two points

Rockwell hardness of pins of a certain type is known to have a mean value of 50 and a standard deviation of 1.1. (round your answers to four decimal places.) (a) if the distribution is normal, what is the probability that the sample mean hardness for a random sample of 8 pins is at least 51?

Apositive number a or the same number a increased by 50% and then decreased by 50% of the result?

Solve the equation using the zero-product property. -3n(7n - 5) = 0 a. 0, -5/7 b. -1/3, -5/7 c. -1/3, 5/7 d. 0, 5/7