Question

Copper sulfate is routinely used to control algae blooms in ponds and lakes. An ichthyologist believes that copper sulfate reduces the number of mucus cells certain species of fish. To test her belief, she recorded the number of mucus cells per square micron in the gill filaments of untreated fish and in fish exposed for 24 hours to copper sulfate at 1 mg/l:

?????????:(16,17,12,18,11,18,12,15,16,14,16)

???????:(10,10,10,10,10,10,10,10,10,10,10,10,10,10)

a. Assuming normality for these data, does the ichthyologist have support for her contention?

b. Develop a 99% confidence interval for ??????????−???????? and explain in words what this calculation represents.

Answer 1

n un treated untreated (1) = 1 n - 165 = 15 SAS 1 (2x - (32) 2) = VA Cerss aller? ) = [2.4495] Exposed (M2): 5- = Szaveta) (933–(E33- (1400 - Motion = 0 cod (42 ) (ali to : Mi = la versus Haikis la (11) The test statistic t= ( 2) 6.17 a at 10 VhT4 (11) P-value = 0.0000 (1r condrsion. Reject to and conclude that the cop species of fish. Deduces the number of mucus cells certain + ] The and cL for (i - H2) = (-2) I (tan. J 1 340 =(15-10) + ( 3-169 x 2.4495) 702) 2 (2.6595 37.3405) The 99% CI [2.66 MM2 < [7:34] 30 u66