Dairy cows ~ The USDA collects and distributes a wide variety of data about agriculture in the United States. One statistic reported each year is the number of milk cows (in thousands) in each state. A random sample of 10 states is selected, with the number of milk cows reported in both 2011 and 2015.

State	2011	2015	Difference
North Carolina	45	47	2
South Dakota	91	106	15
Washington	260	277	17
Colorado	128	146	18
Iowa	204	211	7
Idaho	578	585	7
Massachusetts	13	12	-1
Maryland	52	49	-3
Minnesota	468	460	-8
Nevada	29	29	0
mean	186.8	192.2	5.4
sd	195.444	195.452	8.959

An agricultural researcher wants to conduct a paired difference test to determine if the mean number of milk cows (in thousands) in the US changed between 2011 and 2015.

Round all calculated values to 4 decimal places as appropriate.

1. Which hypotheses should be used to conduct the test?

A. H0:diff=0H0:diff=0 vs. Ha:diff<0Ha:diff<0 B. H0:diff=0H0:diff=0 vs. Ha:diff0Ha:diff0 C. H0:diff<5.4H0:diff<5.4 vs. Ha:diff>5.4Ha:diff>5.4 D. H0:diff=0H0:diff=0 vs. Ha:diff>0Ha:diff>0

Round all calculated values to 4 decimal places as appropriate.

2. Assume the conditions for the hypothesis test are met and find the test statistic and the p-value.test statistic = p-value =

3. Based on the p value we have ?????? evidence that the null model is not a good fit for our observed data.

Little,

Some,

Strong,

Very Strong

Extremely Strong

4. Construct a 90% confidence interval for the mean difference in the number of milk cows (in thousands) between 2011 and 2015.( , )

Round all calculated values to 4 decimal places as appropriate.