Question

Consider the following Data:

Year	Tea (L per person)	Coffee (L per person)
1994	42.4	95.85
1995	42.12	97.28
1996	47.61	87.62
1997	60.86	92.04
1998	55.58	99.21
1999	50.61	95.63
2000	49.89	97.42
2001	56.77	93.93
2002	62.53	95.67
2003	68.31	99.25
2004	69.88	101.31
2005	72.99	101.68
2006	71.36	104.02
2007	90.78	106.09
2008	74.7	105.8
2009	67.15	102.15
2010	67.03	101.15
2011	87.83	104.05
2012	93.4	102.7
2013	78.9	105.28
2014	111.32	106.3
2015	98.39	104.96
2016	105.25	103.57

1. Calculate measures of central tendency and spread for coffee and tea.
2. Create Histograms and Box-Plots for both coffee and tea, displaying the number of years in each interval of consumption in L/person.
3. Create scatter plots for Coffee vs. Year and Tea vs. Year and Coffee vs. Tea.  
4. Create and record the lines of best fit for each and the correlation coefficient.

Answer 1

Here I attach the R code with output

tea=c(42.4,42.12,47.61,60.86,55.58,50.61,49.89,56.77,62.53,68.31,69.88,72.99,71.36,90.78,74.7,67.15,67.03,87.83,93.4,78.9,111.32,98.39,105.25)
coffee=c(95.85,97.28,87.62,92.04,99.21,95.63,97.42,93.93,95.67,99.27,101.31,101.68,104.02,106.09,105.8,102.15,101.15,104.05,102.7,105.28,106.3,104.96,103.57)

year=c(1994:2016)  
mean(tea)
median(tea)
mfv1(tea)
range(tea)
mean(coffee)
median(coffee)
mfv1(coffee)
range(coffee)
hist(coffee)
hist(tea)
boxplot(coffee)
boxplot(tea)
plot(coffee,tea)

plot(year,coffee)
plot(year,tea)

m=lm(coffee~tea)
summary(m)
cor(coffee,tea)

The measure of central tendency are mean, median , mode(mfv-most frequent observation) etc..

Measure of spread is range

range(tea)=111.32-42.12=69.2

range(coffee)=106.30-87.62=18.68

Boxplot of coffee

From the plot it is clear that the distribution is negatively skewed and there is no outliers in the data.

Boxplot of tea

From the plot we can infer that the distribution is positively skewed and there is no outliers in the model.

The correlation between Coffee and tea is 0.769, which implies there is positive linear relatioship exist between the variable tea and coffee.

The obtained model is:

coffee=86.3200+0.1954*tea