I need help please, don't report please bc I really need help bc I couldn't do this like 50 times ​

What kind of bond pays interest which is exempt from tax?

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 ph level of a blueberry is 3.1 what is the hydrogen-ion concentration [h+] for the blueberry