5. An article reported the following data on oxidation-induction time (min) for various commercial oils:

86	104	130	160	180	195	134	145	213	105	145
154	151	137	87	99	95	119	129

(a) Calculate the sample variance and standard deviation. (Round your answers to four decimal places.)

s2	= min2
s	= min

(b) If the observations were reexpressed in hours, what would be the resulting values of the sample variance and sample standard deviation? Answer without actually performing the reexpression. (Round your answer to four decimal places.)

s2	= hr2
s	= hr

6. An article considered various issues associated with determining endotoxin concentration. The following data on concentration (EU/mg) in settled dust for one sample of urban homes and another of farm homes was kindly supplied by the authors of the article.

U:	6.0	5.0	11.0	33.0	4.0	5.0	80.0	18.0	35.0	17.0	23.0
F:	4.0	14.0	11.0	9.0	9.0	8.0	4.0	20.0	5.0	8.9	21.0	9.2	3.0	2.0	0.3

(a)Determine the value of the sample standard deviation for each sample. [Hint:

x_i=237.0

for the urban sample and128.4for the farm sample, and

x_i²=10,079

for the urban sample and1617.94for the farm sample.] (Round your answers to two decimal places.)urban-settlings=farm-settlings=

7. An article described an experiment in which observations on various characteristics were made using minichambers of three different types: (1) cooler (PVC frames covered with shade cloth), (2) control (PVC frames only), and (3) warmer (PVC frames covered with plastic). One of the article's authors kindly supplied the accompanying data on the difference between air and soil temperatures (C).

Cooler	Control	Warmer
1.59	1.92	2.57
1.43	2.00	2.60
1.88	2.19	1.93
1.26	1.12	1.58
1.91	1.78	2.30
1.86	1.84	0.84
1.90	2.45	2.65
1.57	2.03	0.12
1.79	1.52	2.74
1.72	0.49	2.53
2.41	1.90	2.13
2.34		2.86
0.94		2.31
1.34		1.91
1.76

(a)Compare measures of center for the three different samples.

Cooler=

Control=

Warmer=

(b)Calculate the standard deviations for the three different samples. (Round your answers to three decimal places.)

Coolers=

Controls=

Warmers=