A manufacturing company knows that their machines produce parts that are defective on occasion. They have 4 machines producing parts, and want to test if defective parts are dependent on the machine that produced it. They take a random sample of 321 parts and find the following results. Test at the 0.05 level of significance. Machine 1 Machine 2 Machine 3 Machine 4Defective 9 12 15 6Non-Defective 63 70 68 57

Ahypothesis is: a the average squared deviations about the mean of a distribution of values b) an empirically testable statement that is an unproven supposition developed in order to explain phenomena a statement that asserts the status quo; that is, any change from what has been c) thought to be true is due to random sampling order da statement that is the opposite of the null hypothesis e) the error made by rejecting the null hypothesis when it is true