What is the surface area

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?

Will give brainliest for correct answer 8. use the distance time graph to answer these questions: a. what does the graph tell us about the velocity of the car? b. what is the average velocity of the car? (show work) c. is the velocity reflected in the graph positive or negative?d. is there any point on the graph where the car is not moving? how do we know?

(-y to the power of 2 - 4y- to the power of 2 -6 y +3)