Question

A lead-free solder can be made using two different alloys. An important characteristic feature of a solder is its melting point, which is known to follow a Normal distribution. An experiment was conducted using a random sample of 21 pieces of solder made from the two different alloys (1 and 2). In each sample, the temperature at which each of the 21 pieces melted was determined. The mean and standard deviation of the sample for Alloy 1 were M1= 218.9ºC and S1 = 2.7ºC; for Alloy 2 the results were M2 = 215.5ºC and S2 = 3.6ºC. If it is required to test H0: µ1 = µ2 against HA: µ1 ≠ µ2, where µ stands for the population mean, what would be the value of the test statistic?​

Answer 1

Answer:

Use the following information to answer the next five exercises. Two metal alloys are being considered as material for ball bearings. The mean melting point of the two alloys is to be compared. 15 pieces of each metal are being tested. Both populations have normal distributions. The following table is the result. It is believed that Alloy Zeta has a different melting point. \begin{array}{|l|l|l|}\hline & {\text { Sample Mean Melting Temperatures }\left(^{\circ} F\right)} & {\text { Population Standard Deviation }} \\ \hline \text { Alloy Gamma } & {800}&{95} \\ \hline \text { Alloy zeta } & {900} &{105} \\ \hline\end{array} State the null and alternative hypotheses.