In a sale, normal prices are reduced by 13%. The sale price of a DVD recorder is £108.75 Calculate the normal price of the DVD recorder.

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?

Asurvey of 2,000 doctors showed that an average of 3 out of 5 doctors use brand x aspirin.how many doctors use brand x aspirin

Aquadratic equation in standard from is written ax^2= bx+c, where a,b and c are real numbers and a is not zero?