The breaking strengths of cables produced by a certain manufacturer have a mean, , of pounds, and a standard deviation of pounds. it is claimed that an improvement in the manufacturing process has increased the mean breaking strength. to evaluate this claim, newly manufactured cables are randomly chosen and tested, and their mean breaking strength is found to be pounds.

assume that the population is normally distributed. can we support, at the level of significance, the claim that the mean breaking strength has increased? (assume that the standard deviation has not changed.)

perform a one-tailed test. then fill in the table below.

(a) what is the null hypothesis? h0:

(b) what is the alternate hypothesis? h1:

(c) do we use the z, t, chi or f test statistic?

(d) what is the value of the test statistic? round to at least three decimal places

(e) what is the critical value at the 0.1 level of significance? (round to at least three decimal places)

(f) **answer this yes or no** can we support the mean breaking strength has increased?