Question

The changing climate will probably bring more rain to California, but we do not know whether the additional rain will come during the winter wet season or extend into the long dry season in spring and summer. Kenwyn Suttle of the University of California at Berkeley and his coworkers randomly assigned plots of open grassland to three treatments: added water equal to 20% of annual rainfall either during January to March (winter) or during April to June (spring), and no added water (control). Some of the data for plant biomass (in grams per square meter) produced by each plot in a single year are given in the table. Winter 264.1514 Control 129.0538 144.6578 187.7312 291.1431 Spring 318.4182 281.6830 288.8433 382.6673 326.8877 293.8502 172.7772 176.2879 113.2813 141.7525 169.9737 142.1562 117.9808 To access the complete data set, click the link for your preferred software format. Excel Minitab JMP SPSS TI R Mac-TXT PC-TXT CSV CrunchIt!

Answer 1

(a)

	Mean	Std. Dev
Winter	205.17	58.77
Spring	315.39	37.34
Control	136.65	21.69

Option A

(b) The hypothesis being tested is:

H₀: µ_W = µ_S = µ_C

H_a: At least one means is not equal

Option B

Please give me a thumbs-up if this helps you out. Thank you!