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?

0.0051

Step-by-step explanation:

Given: Mean :

Standard deviation :

Sample size :

The formula to calculate z is given by :-

For x= 51

The P Value =

Hence, the probability that the sample mean hardness for a random sample of 8 pins is at least 51 =0.0051

describing distributions is one of the key skills you’ll need to earn a high score on the ap statistics exam. if you need proof of this, just flip through some past exam questions, which can be found at the collegeboard website. you’ll notice that the first free response question is almost always a question requiring you to look at a graph and describe it.

step-by-step explanation: just trying to get points sorry : (