A deficiency of the trace element selenium in the diet cannegatively impact growth, immunity, muscle and neuromuscularfunction, and fertility. The introduction of selenium supplementsto dairy cows is justified when pastures have low selenium levels.Authors of a research paper supplied the following data on milkselenium concentration (mg/L) for a sample of cows given a seleniumsupplement (the treatment group) and a control sample given nosupplement, both initially and after a 9-day period.

Initial Measurement

Treatment	Control
11.3	9.1
9.7	8.7
10.1	9.7
8.5	10.8
10.4	10.9
10.7	10.6
11.8	10.1
9.8	12.3
10.6	8.8
10.4	10.4
10.2	10.9
11.3	10.4
9.2	11.6
10.7	10.9
10.8
8.2

After 9 Days

Treatment	Control
138.3	9.4
104	8.8
96.4	8.8
89	10.1
88	9.7
103.8	8.7
147.3	10.3
97.1	12.3
172.6	9.4
146.3	9.5
99	8.3
122.3	8.9
103	12.5
117.8	9.1
121.5
93

(a)

Use the given data for the treatment group to determine if thereis sufficient evidence to conclude that the mean seleniumconcentration is greater after 9 days of the selenium supplement.(Use α = 0.05. Use μ_d =μ_initial − μ_9-day.)

Find the test statistic. (Round your answer to two decimalplaces.)

t =

Find the df.

df =

Find the P-value. (Use technology to calculate theP-value. Round your answer to three decimal places.)

P-value =

(b)

Are the data for the cows in the control group (no seleniumsupplement) consistent with the hypothesis of no significant changein mean selenium concentration over the 9-day period? (Useα = 0.05. Use μ_d =μ_initial − μ_9-day.)

Find the test statistic. (Round your answer to two decimalplaces.)

t =

Find the df.

df =

Find the P-value. (Use technology to calculate theP-value. Round your answer to three decimal places.)

P-value =