Please help I need help on this question I have no idea how to do it

What is the value of x in the figure below? if necessary, round your answer to the nearest tenth of a unit. 12 d 4 b оа. 3.1 ов. 6.9 ос. 4 od. 12

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?

Complete the table for different values of x in the polynomial expression -7x2 + 32x + 240. then, determine the optimal price that the taco truck should sell its tacos for. assume whole dollar amounts for the tacos.