# Question: A new process has been developed for applying photoresist to

A new process has been developed for applying photoresist to 125-mm silicon wafers used in manufacturing integrated circuits. Ten wafers were tested, and the following photoresist thickness measurements (in angstromx × 1000) were observed: 13.3987, 13.3957, 13.3902, 13.4015, 13.4001, 13.3918, 13.3965, 13.3925, 13.3946, and 13.4002.

(a) Test the hypothesis that mean thickness is 13.4 × 1000 Å. Use a = 0.05 and assume a two-sided alternative.

(b) Find a 99% two-sided confidence interval on mean photoresist thickness. Assume

(c) Does the normality assumption seem reasonable for these data?

(a) Test the hypothesis that mean thickness is 13.4 × 1000 Å. Use a = 0.05 and assume a two-sided alternative.

(b) Find a 99% two-sided confidence interval on mean photoresist thickness. Assume

(c) Does the normality assumption seem reasonable for these data?

**View Solution:**## Answer to relevant Questions

A machine is used to fill containers with a liquid product. Fill volume can be assumed to be normally distributed. A random sample of ten containers is selected, and the net contents (oz) are as follows: 12.03, 12.01, 12.04, ...Suppose that x1 ~ N(1, 12) and x2 ~ N(2, 22), and that x1 and x2 are independent. Develop a procedure for constructing a 100(1 − )% confidence interval on 1 − 2, assuming that 12 and 22 are ...Two different types of glass bottles are suitable for use by a soft-drink beverage bottler. The internal pressure strength of the bottle is an important quality characteristic. It is known that 1 = 2 = 3.0 psi. From a ...There is a typographical error in the hypotheses (should be 22) in early printings of the 7th edition; this solution is for the correct hypotheses. Develop a test for the hypotheses H0 : 1 22 H1 : 1 ...Plot the residuals from Exercise 4.36 against the firing temperatures. Is there any indication that variability in baked anode density depends on the firing temperature? What firing temperature would you recommend using?Post your question