Solve for d and graph the solution. d - 20 < -12 or d - 20 > -5
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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 standard deviation for a set of data is 5.5. the mean is 265. what is the margin of error?

During a wright loss challenge your friend goes from 125 pounds to 100 pounds.what was the percent weight loss