A sample was taken with 15 observations of soil tests from North Carolina rural yards. We would like to determine whether there is reason to believe the nitrate levels differ from the national average. Our sample average shows 8.19 parts per million (ppm) nitrate concentration with a sample standard deviation of 3.95 ppm. Suppose the national average for rural yard is 6.25 ppm.
Conduct the hypothesis test using a 90% confidence level and answer the following questions. For all numbers, please round to the nearest hundredths.
standard error = 3.95/sqrt(15) = 1.0199
degree of freedom = 15 - 1 = 14
Test statistic,
t = (xbar - mu)/(s/sqrt(n))
t = (8.19 - 6.25)/(3.95/sqrt(15))
t = 1.902
P-value Approach
P-value = 0.0779
As P-value < 0.1, reject the null hypothesis.
differ
A sample was taken with 15 observations of soil tests from North Carolina rural yards. We...
the minimum wage in 15 states Name of state Data value State 1 Alabama 2.2 State 2 Arkansas 0.7 State 3 Connecticut 0.9 State 4 Florida 6.6 State 5 Idaho 0.6 State 6 Iowa 1.2 State 7 Louisiana 2.9 State 8 Massachusetts 1.9 State 9 Mississippi 1.3 State 10 Nebraska 0.5 State 11 New Jersey 2.2 State 12 North Carolina 4.6 State 13 Oklahoma 1.4 State 14 Rhode Island 0.4 State 15 Tennessee 3.4 Analysis: Compute the mean and standard...