at an assembly plant for light trucks, routine monitoring of the quality of welds

yields the following data:

Number of Welds

High Quality Low Quality

Day Shift 467 42

Night Shift 442 34

Can you conclude that the quality varies among the shifts?

(a) State the null hypothesis.

(b) Compute the expected values under the null hypothesis.

(c) Compute the value of the chi-square statistic.

(d) Find the p-value (or critical value). What can you conclude at a = 0.1 level of significance?