Question

Using program R, please help solve:
(if answered by Tuesday 6/11 evening, I will rate)

3.31 The data set coins (UsingR) contains the number of coins in a change bin and the years they were minted. Do the following: 1. How much money is in the change bin? 2. Make a barplot of the years. Is there a trend? 3. Use cut to construct a barplot by decade. 4. Make a contingency table of the year and the value. Does it look like the two variables are associated? Why?

Answer 1

The following R code is used to solve the given problems (Part wise)

***********************************************************************************************************************install.packages("UsingR")
library(UsingR)

sum(coinsSvalue) [1] 25.93

barplot (table(coinsSyear), main-"Year Count Barplot", xlab-"Years" A+

Year Count Barplot LO 1929 1967 1976 1985 1994 2003 Years 0

years_cut <- cut (coins Syear,seq(1920,2010, by-10),include. lowest-TRUE, labels paste (192:200, ,sep="")) +


table(years_cut) years_cut 192* 193 194* 195* 196* 197* 198* 199* 200* 99 147 3 2 3 16 43 58

barplot (table(years_cut))

192* 194* 196* 198* 200* 0 204060 80 120

> table(coins)
      value
year   0.01 0.05 0.1 0.25
  1929    2    1   0    0
  1936    0    0   1    0
  1939    0    0   1    0
  1955    0    0   0    1
  1959    1    0   0    0
  1960    1    0   0    0
  1964    1    0   0    0
  1965    2    1   0    0
  1966    1    1   0    0
  1967    0    1   0    0
  1968    1    0   0    1
  1969    2    0   1    0
  1970    1    1   0    2
  1971    3    0   2    1
  1972    2    0   0    1
  1973    1    0   0    0
  1974    1    1   1    0
  1975    4    1   0    4
  1976    2    1   0    1
  1977    4    2   0    1
  1978    5    1   0    0
  1979    1    1   0    0
  1980    1    1   0    0
  1981    7    1   2    0
  1982    9    1   2    1
  1983    7    3   1    0
  1984    7    3   0    1
  1985    2    4   1    1
  1986    3    0   1    1
  1987    7    1   1    0
  1988    7    3   2    2
  1989    4    0   3    2
  1990    3    3   1    2
  1991    2    1   1    1
  1992    6    0   0    6
  1993    8    3   1    2
  1994    7    1   2    1
  1995    6    2   3    2
  1996    7    3   0    4
  1997    6    2   1    3
  1998    5    1   0    5
  1999   16    2   6    1
  2000   15    4   3    8
  2001   13    5   0    7
  2002   19    3   5    3
  2003    1    0   0    2

************************************************************************************************************************

Interpretation of the Contingency table

Yes there is an association between Years and Value, as with increase in the years, there is a clear increase in Value.