Your employer, Apricot Computers, Inc., is interested in locating a new manufacturing facility in North Carolina. For easier access to their markets along the East coast and in the Atlanta area Apricot would like to locate the facility in the vicinity of Interstate 85.
Since Apricot is also interested in the educational level of the local workforce in the locations under consideration, you are told to obtain an estimate of the proportion p of the population over age 25 with a bachelors degree in each of several counties in the vicinity of Interstate 85, and present your results to the Apricot CEO.
To enhance your presentation to the CEO, you would like to show a plot of your estimates on a map of North Carolina. The data that you collected for 12 North Carolina counties in the vicinity of I85 is in this text file (right click the file and choose "open in new window" or "open in new tab" to open the file): BAdegrees. You can use statcrunch to plot this data on a Google map as follows:
- Right click Google maps at statcrunch.com and choose "open in new window" or "open in new tab" to open the Google mapping facility at statcrunch.com.
- Below the map in the Location information window copy and paste the location information from the above text file.
- In the Legend title window type the word Counties.
- In the Optional legend information window copy and paste the optional legend information from the above text file.
- Click the Plot locations button below the Optional legend information window.
- Your data will begin to plot on the Google map (the data will take a few seconds to appear since Google servers will process only one "geocode" request per second).
- The map will have "baloon" markers showing the location of the counties. Point to a marker to see the name and proportion for that county; click on the marker to open a window with the information. Alternatively, click a county name in the list to the right of the map to see the location and information for that county.
Question 1. A major trucking company is located in Danville, Virginia. Simply by looking at the map, which county for which you have an estimated proportion is closest to Danville? (click-and-hold on the map and drag it down a little to see Danville, VA on the map).
A community college in Statesville, NC will offer technical training to Apricot employees at a reduced cost. The Apricot CEO would like a 95% confidence interval for p, the proportion of the population over the age of 25 with a bachelors degree, in the county closest to Statesville, NC.
Question 2. Calculate the confidence interval for the county closest to Statesville; assume the sample size n = 750.
lower bound (use 4 decimal places)
upper bound (use 4 decimal places).