Calculating Overall mean and Inferential tests

I. Which measure of central tendency would you use to summarize the data below?
11.2, 13.9, 15.8, 16.6, 28.2, 12.1, 17.3
a. Arithmetic mean
b. Mode
c. Median
d. Weighted mean

II. Use the following scenario presented below to answer questions 1 to 2: January rainfall (mm) was recorded at four weather stations along a coastline for several years. The Mean and sample size for each sample are summarized below. Sample 1: n=5 and x'=53.8; Sample 2: n=5 and x'=47.4; Sample 3: n=5 and x'=52.2; Sample 4: n=4 and x'=43.8
1. Calculate the overall mean for the 4 samples.
2. Which inferential test would you use to determine if there is a difference in rainfall between the sample 2 and 3? (Note: based on previous experience, you can assume that the rainfall data have normal distributions.)
a. Two or more sample chi-square test
b. Linear regression
c. Two independent sample t-test
d. Pearson's correlation coefficient