We want an estimate of the mean time required for ships of a particular class to cross the Pacific Ocean from San Francisco to Tokyo. Little is known about the distribution of the mean time for this class of ships to cross the ocean due to the age variation of the ships. It is believed, however, the travel time is not normally distributed. From a sample of the logs of 49 ships, randomly selected, we observe the times shown in the data sets Ships.

For your convenience, dataset Ships are located on Blackboard under
¡¥Quizzes and Tests¡¦. Additionally, the information is also shown in Table 1 at the end of this test.

With ƒÑ = 0.10, construct a confidence interval estimate of ƒÝ, the mean time for all ships of this class.

Which distribution did you use (t or unit normal (Z))? _________________


ANSWER: I am ______% confident that

__________________________________________
(enter interval estimate)

We do not have access to your information.

To construct a confidence interval estimate for the mean time required for ships of this particular class to cross the Pacific Ocean, we can use the t-distribution.

Here's how you can calculate the confidence interval:

Step 1: Calculate the sample mean (x̄) and the sample standard deviation (s) from the given dataset of 49 ship logs.

Step 2: Determine the critical value (t*) corresponding to the desired confidence level and the degrees of freedom (n-1). In this case, with a confidence level of 90% and 49-1=48 degrees of freedom, you can find the t* value from the t-distribution table or use statistical software.

Step 3: Calculate the standard error (SE) using the formula SE = s / sqrt(n), where n is the sample size.

Step 4: Calculate the margin of error (E) using the formula E = t* * SE.

Step 5: Calculate the lower and upper bounds of the confidence interval using the formulas lower bound = x̄ - E and upper bound = x̄ + E.

Step 6: Write the confident interval estimate as [lower bound, upper bound] with the specified confidence level.

So, to fill in the missing parts of your statement:

Which distribution did you use (t or unit normal (Z))? _t-distribution_

ANSWER: I am ______% confident that the true mean time for all ships of this class to cross the Pacific Ocean lies within the interval estimate [lower bound, upper bound] (fill in the values accordingly).

Remember to substitute the calculated values from the dataset into the appropriate formulas to find the actual confidence interval estimate.