A company has a new process for manufacturing large articial sapphires. In a trial run, 37 sapphires are randomly selected. The mean weight for thesegems isx

=6.75

x=6.75carats, and the sample standard deviation iss=0.33

s=0.33carat. Let

be the mean weight for the distribution ofall sapphiresproduced by the new process.(Show your work, no work shown, no credit given)

• What is the degrees of freedom in this problem?

• Use table or Technology to find t-critical value with degrees of freedom found above and with=0.05
• =0.05significance level.

• Find the Margin of error (E)

• Find a 95% confidence interval for

• Interpret the condence interval in the context of the problem.
• Tell me one thing you like about this course.
• One thing you want me to improve.