Homework Assignment 7

GEOG 3900 Spatial Analysis

Spring 2000
due April 9

Sample Comparison

You have surveyed vanilla growers in two rural areas in Mexico. From your survey results, you are able to determine how far (in kilometers) growers must go to take their beans to a processing plant in Chocolatlco. Two of the villages give the following distance summary statistics:

Village	$\bar{x}$	$s$	$n$
San Isidro de Nezahualcoyotl	26.2	6.5	16
Santiago de Ixtlilxochitl	21.9	2.7	8

The farmers union in the first village (Organización de Cultivadores de Vainilla Nezahualcoyotlcotecas) have argued, since they have to travel on an average of 5 km. further to bring their produce to the plant at Chocolatlco, that they should receive a small subsidy each harvest season. How can you test the veracity of their complaint?

1. Since the test statistic is dependent on whether the variances are comparable, first test the null hypothesis $H_0: \sigma_1^2 = \sigma_2^2$.
   
   
   

2. Using the $\hat{\sigma_{\bar{x}}}$ from the last step, test whether the farmers in San Isidro truly have to travel 5 km. further than their counterparts in Santiago ( $H_0: \vert\mu_1 - \mu_2\vert \leq D_0$)

Multiple Comparison

You are working with a research crew that is looking at worm farmers on either side of a fishing resort. Worm production was measured, with the following results:

Producer	region	production stats (kg./ha.day)
Billy Bob's	North	6 7 6 6 5 4
Bobby Lou's	North	5 5 6 7 3 4
Mobli's Tavern	South	6 6 6 7 6 5
Delaney's	South	5 5 4 3 2 5
Phineas Franklin and Freddy	South	6 6 6 3 6 6
Emert Poultry Sub.	North	3 3 3 7 3 5
Heatherford Downs	North	2 5 8 9 22 5

• Test the hypothesis that the North side is more productive than the south.
  • What is your test hypothesis?
    
    
    
    
    
    
  • Are the variances between populations equal?
    
    
    
    
    
    
    
    
  • Show your test statistic and state your conclusions
    
    
    
    
    
    
    
    
    
    

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Homework Assignment 7

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