Does anyone know how to do numbers 5,6,7,8? plz !

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?

The average number of vehicles waiting in line to enter a parking lot can be modeled by the function f left parenthesis x right x squared over 2 left parenthesis 1 minus x right parenthesis endfraction , where x is a number between 0 and 1 known as the traffic intensity. find the rate of change of the number of vehicles waiting with respect to the traffic intensity for the intensities (a) xequals0.3 and (b) xequals0.6.

Is trapezoid abdc the result of a dilation of trapezoid mnpq by a scale factor of ? why or why not? yes, because ab and cd are each the lengths mn and qp. yes, because sides ab and cd are parallel to sides mn and qp. no, because ab is the length mn but cd is the length qp. no, because sides ab and cd have different slopes from sides mn and qp.