Question 1: la base des données et les variables ht et circ

eucalyptus=read.csv("C:/Users/pc carrefour/Desktop/eucalyptus.txt",header = TRUE, sep=";")
View(eucalyptus)
attach(eucalyptus)
ht 
##    [1] 18.25 19.75 16.50 18.25 19.50 16.25 17.25 19.00 16.25 17.50 15.50
##   [12] 19.75 22.00 18.25 18.25 20.50 16.00 18.00 20.25 19.75 19.00 19.75
##   [23] 17.50 21.00 21.75 23.00 22.25 23.00 23.00 19.00 23.25 24.00 22.00
##   [34] 19.00 19.75 22.25 21.75 23.25 24.25 23.25 24.25 24.50 23.00 22.50
##   [45] 21.25 19.75 22.50 18.75 12.50 18.00 23.50 24.00 23.75 23.75 23.25
##   [56] 21.25 23.25 20.50 23.25 22.25 23.75 24.75 24.25 21.25 20.75 19.75
##   [67] 22.25 20.25 18.75 21.25 22.00 19.75 16.25 21.00 18.75 21.75 19.25
##   [78] 19.75 21.25 22.00 21.75 20.25 23.25 18.25 22.75 20.75 18.50 21.75
##   [89] 19.75 23.75 23.25 22.50 22.25 22.25 23.50 24.25 21.25 22.50 23.00
##  [100] 21.75 21.25 22.00 15.75 21.50 21.75 21.25 23.00 20.75 21.00 22.25
##  [111] 22.25 22.75 23.25 21.25 21.75 22.75 22.25 19.00 19.25 23.75 22.50
##  [122] 23.25 22.75 23.25 23.25 22.75 15.25 23.00 22.75 22.75 23.25 23.00
##  [133] 23.25 23.75 23.00 24.75 25.25 23.75 16.75 22.75 24.25 15.25 23.25
##  [144] 23.25 24.50 23.25 20.75 25.25 22.25 23.75 23.75 24.25 23.75 23.75
##  [155] 22.25 24.75 25.25 24.25 24.75 24.75 22.25 22.25 25.00 22.50 24.00
##  [166] 25.25 24.25 24.75 25.75 23.75 22.50 23.50 20.75 23.75 23.25 22.00
##  [177] 23.25 25.75 25.00 26.00 26.00 23.00 20.25 23.75 23.00 24.25 24.75
##  [188] 24.75 24.25 22.50 23.25 21.75 22.25 21.25 23.25 21.75 23.50 22.50
##  [199] 22.25 22.75 22.25 22.25 22.75 21.25 22.75 22.25 22.75 18.75 23.25
##  [210] 23.50 22.25 22.75 23.75 21.75 23.00 23.25 22.25 21.75 21.75 22.25
##  [221] 21.50 22.00 22.25 22.25 23.00 24.75 23.00 23.50 23.75 25.25 24.00
##  [232] 24.25 24.75 23.00 23.75 22.00 22.00 22.25 22.25 23.25 23.25 19.25
##  [243] 23.25 23.25 23.25 23.75 21.75 20.75 23.25 23.00 19.50 23.00 19.00
##  [254] 22.00 21.75 22.25 23.25 22.75 23.25 21.50 22.50 23.25 22.25 21.25
##  [265] 25.50 24.25 24.75 23.75 23.25 23.25 18.25 23.25 23.25 17.75 17.75
##  [276] 20.25 20.75 18.50 20.00 20.25 23.25 20.75 20.75 20.50 19.25 14.75
##  [287] 20.75 19.75 20.00 19.75 19.75 19.75 18.50 19.50 18.75 19.75 21.25
##  [298] 21.00 18.50 20.75 20.00 19.25 19.50 14.50 20.00 21.50 22.25 16.00
##  [309] 21.25 22.25 22.50 21.50 22.75 21.25 20.50 22.25 21.25 11.25 20.50
##  [320] 19.25 17.75 19.50 13.75 16.75 14.00 16.50 19.50 14.00 15.00 16.75
##  [331] 19.75 20.75 21.00 20.50 19.75 15.25 18.50 20.00 21.50 22.75 23.00
##  [342] 22.25 21.75 22.25 22.00 22.50 21.75 19.00 21.75 20.75 22.00 20.25
##  [353] 19.75 22.00 20.25 19.25 22.25 21.25 19.75 22.50 22.75 21.75 20.75
##  [364] 23.75 20.25 22.75 21.75 19.00 21.00 19.75 21.25 22.00 16.25 17.50
##  [375] 18.25 18.00 22.00 20.75 21.25 21.25 21.50 20.75 16.75 19.25 15.75
##  [386] 17.25 17.25 18.25 20.75 16.75 17.50 15.25 20.75 19.75 17.25 21.25
##  [397] 21.50 20.75 18.75 19.25 20.75 20.75 20.75 23.50 23.25 18.00 16.50
##  [408] 24.75 17.75 23.75 24.25 17.25 17.00 19.50 18.00 15.75 19.25 19.75
##  [419] 18.50 19.00 20.25 22.75 21.75 20.75 20.75 21.50 22.00 21.00 16.25
##  [430] 22.00 21.00 21.50 21.00 18.00 20.50 21.25 20.50 17.25 19.25 18.75
##  [441] 20.00 21.00 19.00 19.00 21.00 20.25 20.00 21.75 19.50 20.50 19.75
##  [452] 20.75 20.75 19.00 20.00 19.75 18.75 19.25 20.50 19.25 19.25 19.75
##  [463] 19.75 19.25 20.50 18.25 17.00 21.00 20.00 17.75 15.75 18.75 23.25
##  [474] 23.25 19.75 23.75 24.75 23.50 15.25 20.25 22.75 23.25 20.25 20.50
##  [485] 21.75 21.25 23.25 19.75 23.25 19.50 22.75 15.00 23.75 23.00 21.75
##  [496] 23.25 22.75 24.25 24.75 22.75 24.00 21.75 23.75 25.00 24.25 23.25
##  [507] 22.25 23.50 26.00 25.25 24.75 21.75 21.75 21.75 21.75 21.50 22.25
##  [518] 19.50 21.25 22.00 17.25 19.00 18.25 14.25 19.00 15.00 15.00 17.00
##  [529] 18.50 16.50 17.00 16.00 13.50 20.50 21.00 17.75 18.25 18.50 16.50
##  [540] 21.00 16.00 20.75 18.75 19.25 16.75 19.00 20.75 18.25 20.00 23.00
##  [551] 23.00 24.50 20.75 23.50 16.00 24.00 21.75 23.50 24.25 23.25 22.75
##  [562] 16.00 22.75 24.25 20.75 22.25 16.75 21.75 15.25 20.00 16.75 17.75
##  [573] 12.75 20.50 19.25 23.50 20.75 22.25 22.50 21.75 20.75 22.25 23.75
##  [584] 22.75 23.25 22.75 22.25 22.25 22.75 21.75 23.25 21.00 21.75 15.50
##  [595] 22.50 22.75 19.25 22.50 19.50 21.25 19.75 21.75 20.25 20.75 18.25
##  [606] 21.50 22.75 21.75 18.00 21.25 18.75 21.25 15.75 19.50 19.25 18.00
##  [617] 18.50 22.75 21.75 22.00 21.50 22.00 20.25 20.75 21.25 19.50 22.25
##  [628] 21.00 22.00 20.50 20.75 20.50 21.50 21.25 19.75 21.75 21.75 18.50
##  [639] 21.25 21.25 23.00 22.75 22.00 22.00 20.50 22.75 22.75 23.75 13.75
##  [650] 23.25 22.75 22.25 22.25 20.75 19.75 22.25 20.00 22.50 22.00 17.75
##  [661] 22.75 23.25 22.25 23.75 23.75 22.50 17.75 24.00 18.50 23.25 23.50
##  [672] 21.50 23.50 23.00 22.75 24.75 23.25 23.75 23.75 24.50 18.50 21.50
##  [683] 21.25 23.00 21.00 23.75 23.00 21.25 20.00 22.25 22.25 23.25 22.75
##  [694] 22.25 23.75 22.25 23.50 24.75 21.75 22.50 21.50 23.25 21.00 23.50
##  [705] 22.25 22.75 22.50 22.75 20.75 19.25 21.75 23.50 22.25 12.75 25.25
##  [716] 25.25 21.25 23.25 23.75 20.75 24.25 22.75 24.75 22.00 24.75 24.25
##  [727] 24.75 21.75 23.75 21.25 21.25 24.25 22.25 23.00 22.50 19.75 23.25
##  [738] 21.00 23.00 20.00 23.00 22.50 20.25 20.00 22.00 22.00 22.50 22.25
##  [749] 22.25 20.25 21.00 22.75 19.75 21.75 23.25 21.50 24.00 23.75 18.75
##  [760] 22.00 24.50 24.50 21.50 19.50 22.50 20.25 21.25 21.75 21.00 22.00
##  [771] 20.50 18.25 23.75 23.25 23.75 24.25 23.75 23.25 24.50 23.25 22.25
##  [782] 22.75 22.75 23.25 24.25 23.75 24.00 23.50 24.75 24.25 19.50 24.50
##  [793] 20.00 24.00 24.25 23.75 21.00 23.00 16.25 23.25 22.50 23.75 21.00
##  [804] 22.50 23.75 21.50 22.00 22.00 21.75 22.25 23.75 22.25 23.75 23.25
##  [815] 20.25 18.50 21.25 22.50 23.75 23.00 23.75 23.75 24.75 22.75 22.50
##  [826] 22.75 22.00 22.50 23.25 22.00 21.50 21.75 21.50 20.00 20.25 16.00
##  [837] 19.50 19.25 19.50 19.25 21.25 22.75 21.75 21.25 23.25 23.00 23.75
##  [848] 15.75 19.75 19.25 20.50 17.00 21.00 20.00 20.00 21.75 21.50 19.75
##  [859] 21.25 20.75 21.00 20.25 21.50 20.25 19.50 20.00 19.00 18.75 20.75
##  [870] 20.50 20.75 19.50 19.75 20.75 20.50 20.50 20.25 20.75 20.25 20.25
##  [881] 20.50 20.25 20.00 20.25 20.00 19.75 20.50 16.50 16.00 19.25 12.75
##  [892] 15.00 19.00 18.25 20.25 18.75 19.50 18.75 23.50 23.00 20.50 22.25
##  [903] 22.25 23.75 21.25 22.25 21.75 21.75 21.25 21.25 20.25 20.00 21.25
##  [914] 21.00 19.75 19.75 21.50 23.50 22.75 15.50 22.25 21.50 19.25 23.00
##  [925] 22.25 21.25 18.00 23.75 22.75 22.25 20.25 11.50 21.50 20.75 21.75
##  [936] 21.25 21.75 16.00 21.50 21.75 16.00 16.75 16.00 14.50 20.25 19.75
##  [947] 14.75 18.00 20.00 17.50 20.75 17.50 19.00 20.00 18.50 17.75 16.25
##  [958] 15.25 18.25 17.00 19.75 13.50 20.00 21.00 21.50 17.00 13.50 13.75
##  [969] 20.75 22.75 24.25 18.25 19.25 21.25 23.75 23.25 21.50 14.50 19.75
##  [980] 17.25 16.25 18.50 17.25 16.25 17.75 16.00 18.75 21.00 19.00 21.00
##  [991] 21.00 18.00 18.50 19.50 18.25 20.25 20.50 20.25 21.25 22.75 21.50
## [1002] 19.25 21.25 20.25 14.50 19.25 19.50 17.00 19.50 17.50 21.50 19.25
## [1013] 20.75 21.75 20.50 21.75 21.00 22.25 19.75 21.25 20.75 20.00 19.25
## [1024] 18.50 20.50 20.00 19.50 18.50 19.50 20.75 19.00 19.50 19.50 20.50
## [1035] 21.25 19.50 18.50 20.00 19.00 18.00 20.25 17.50 17.50 19.25 13.00
## [1046] 23.50 21.75 24.50 23.75 22.75 25.50 23.75 23.75 22.00 17.00 22.25
## [1057] 20.00 23.25 22.50 21.25 16.75 22.75 22.00 17.75 21.00 21.25 20.25
## [1068] 22.25 20.75 24.75 23.75 23.25 20.50 22.75 24.25 21.75 25.25 24.25
## [1079] 17.75 24.25 21.75 24.25 23.00 22.75 25.25 23.75 24.75 23.00 24.50
## [1090] 22.75 22.25 25.25 23.75 24.25 22.75 22.25 24.50 21.25 21.25 20.50
## [1101] 22.00 20.75 21.50 20.50 20.50 19.75 19.50 21.75 19.75 18.00 20.00
## [1112] 20.00 19.00 17.75 19.50 17.25 18.75 20.75 19.00 20.75 22.00 16.75
## [1123] 17.50 21.25 15.25 21.25 21.75 18.25 22.50 14.00 21.50 23.25 23.75
## [1134] 18.00 23.75 24.75 19.50 22.25 24.25 21.00 21.50 23.75 22.75 21.75
## [1145] 21.75 22.25 23.50 23.25 22.50 23.50 25.50 23.75 20.75 20.25 21.25
## [1156] 24.75 19.25 20.00 19.50 22.25 19.75 19.25 21.75 22.75 20.25 20.50
## [1167] 21.25 21.75 21.50 20.25 22.25 19.25 22.25 20.75 18.25 22.75 21.25
## [1178] 20.00 24.25 22.50 22.75 24.25 23.75 22.50 21.75 22.00 22.50 23.25
## [1189] 21.50 23.00 21.25 21.00 22.75 21.75 22.75 21.00 21.75 23.25 23.00
## [1200] 22.25 21.25 24.00 15.75 15.75 23.75 21.25 23.75 25.50 17.00 21.50
## [1211] 21.75 25.25 24.75 22.75 24.25 24.25 23.00 25.25 25.25 24.75 24.75
## [1222] 25.25 20.75 25.75 23.25 23.75 27.00 17.75 25.75 16.25 26.75 24.25
## [1233] 27.75 12.50 19.75 25.75 24.25 25.50 22.25 24.75 26.00 25.50 21.75
## [1244] 21.75 23.25 23.25 21.50 22.25 22.75 24.25 22.25 23.00 23.25 23.25
## [1255] 24.25 24.25 24.25 15.00 25.25 25.50 25.25 24.25 22.50 25.00 25.25
## [1266] 24.25 24.25 21.75 24.00 22.75 20.00 23.25 16.50 21.00 23.75 22.00
## [1277] 25.00 24.75 24.75 25.25 14.25 25.00 25.25 23.75 23.25 22.75 22.25
## [1288] 23.00 22.75 24.25 24.25 22.50 26.50 17.50 25.75 24.25 24.50 24.25
## [1299] 25.00 19.50 24.75 18.50 16.75 22.00 19.25 21.50 18.75 17.75 21.00
## [1310] 19.25 20.75 20.00 19.50 20.75 20.00 21.25 20.50 20.50 21.75 21.25
## [1321] 21.75 22.00 23.75 22.25 21.50 17.25 20.00 16.25 19.75 19.75 18.25
## [1332] 20.50 20.25 23.25 21.50 22.75 22.75 22.75 21.75 22.25 21.75 21.25
## [1343] 22.75 17.00 23.25 22.50 23.50 20.50 22.00 21.50 22.25 21.75 23.00
## [1354] 22.25 22.25 22.75 18.50 18.25 21.00 18.75 21.75 23.00 21.75 20.75
## [1365] 20.75 22.00 21.75 20.25 17.00 20.75 22.25 21.25 23.00 22.50 21.25
## [1376] 21.75 22.75 20.00 22.25 18.75 18.50 18.25 18.25 20.50 18.00 20.75
## [1387] 18.75 19.00 20.25 22.50 19.00 21.00 20.75 22.00 18.25 20.50 23.00
## [1398] 23.75 22.50 22.25 23.00 23.75 16.75 24.75 22.25 22.25 22.75 21.75
## [1409] 22.00 22.00 22.00 23.25 22.75 22.25 22.75 22.75 21.50 22.75 21.25
## [1420] 22.75 22.50 22.25 21.25 20.25 16.50 17.00 20.25 20.25 19.75
circ
##    [1] 36 42 33 39 43 34 37 41 27 30 26 35 39 31 27 35 27 35 40 41 38 38 39
##   [24] 42 46 56 53 54 53 38 53 59 50 38 44 43 47 54 56 56 57 58 52 52 47 44
##   [47] 49 37 32 35 56 58 52 54 58 43 51 40 52 46 54 56 55 46 47 43 52 40 36
##   [70] 47 51 39 34 48 41 48 37 43 45 50 52 45 53 35 46 41 35 43 36 56 52 49
##   [93] 46 47 57 61 46 54 57 49 44 44 31 42 41 41 49 38 39 43 54 53 56 46 44
##  [116] 55 50 36 35 56 46 52 48 51 47 50 28 49 49 46 47 47 50 48 50 58 60 55
##  [139] 32 52 54 29 55 59 60 49 39 65 49 62 54 63 54 54 58 60 59 62 57 59 57
##  [162] 47 62 59 58 65 62 58 65 58 45 54 47 54 54 47 60 64 64 66 60 43 36 49
##  [185] 42 55 54 52 48 54 59 55 55 48 59 53 59 56 51 49 51 46 45 41 51 46 48
##  [208] 38 55 56 52 49 55 49 52 53 55 52 53 52 46 55 54 50 50 62 51 51 53 57
##  [231] 55 54 58 58 57 53 53 48 47 56 56 37 46 49 53 49 41 35 50 46 42 59 32
##  [254] 59 50 56 59 50 56 48 51 60 55 43 55 55 59 51 49 57 39 55 53 35 41 50
##  [277] 53 46 52 46 49 42 42 42 39 31 45 42 41 41 42 43 36 42 36 39 47 46 35
##  [300] 43 42 39 43 29 47 46 50 32 52 58 54 51 54 53 49 55 57 26 53 47 42 45
##  [323] 31 39 27 33 40 26 28 34 44 45 55 45 41 33 39 44 53 58 59 55 50 53 55
##  [346] 54 53 37 52 47 46 41 40 48 45 40 47 45 39 55 56 51 44 52 39 60 49 46
##  [369] 57 49 56 56 35 35 37 35 50 44 45 45 40 38 35 43 32 35 36 36 47 34 34
##  [392] 28 44 43 36 44 44 42 36 36 44 48 45 55 48 35 35 55 32 47 51 31 34 40
##  [415] 37 29 41 43 42 43 43 54 46 48 44 48 48 41 38 52 47 51 45 41 47 53 49
##  [438] 33 43 38 42 43 41 37 49 45 43 58 42 49 48 49 53 45 51 53 45 41 44 44
##  [461] 43 50 43 40 42 35 33 46 41 38 33 37 48 49 34 54 53 52 30 44 56 59 41
##  [484] 47 53 45 57 45 55 43 52 31 59 60 50 57 54 60 61 52 55 47 59 62 61 58
##  [507] 51 56 68 63 61 56 49 49 54 47 55 39 47 49 40 49 46 31 51 33 33 38 46
##  [530] 37 40 35 30 36 41 30 36 36 31 42 26 41 37 38 36 40 44 35 42 58 58 64
##  [553] 50 56 39 64 47 63 60 58 58 33 54 60 42 49 32 44 29 41 30 33 27 41 40
##  [576] 56 45 54 55 48 48 52 53 50 53 49 51 51 50 52 63 52 54 32 58 57 44 55
##  [599] 47 43 41 50 42 44 41 48 55 50 39 46 40 47 35 46 39 34 39 49 41 50 48
##  [622] 48 43 42 48 38 47 48 47 42 46 47 52 43 46 50 51 43 46 45 44 49 44 42
##  [645] 38 47 50 56 28 56 48 58 48 39 41 54 41 52 50 36 49 49 55 54 49 50 35
##  [668] 56 38 55 52 46 55 50 54 64 55 55 57 60 34 57 49 55 50 62 57 47 52 51
##  [691] 51 51 49 50 54 44 53 61 46 52 55 57 46 55 53 56 52 58 51 41 48 56 52
##  [714] 27 61 65 48 58 56 51 59 50 54 44 57 51 52 44 53 40 49 57 52 55 50 45
##  [737] 59 42 48 41 49 42 39 38 45 53 56 49 51 39 47 52 36 47 55 42 57 60 36
##  [760] 49 61 56 53 39 57 46 53 56 53 54 46 35 50 53 53 55 51 57 63 54 49 51
##  [783] 50 55 64 55 64 61 65 61 43 63 45 63 55 53 42 48 29 51 46 49 47 53 55
##  [806] 52 50 48 53 57 59 56 58 60 44 39 52 56 60 54 60 56 58 55 54 53 49 54
##  [829] 56 50 49 45 61 53 56 36 50 41 47 47 43 55 39 43 52 50 46 33 44 40 47
##  [852] 35 46 38 45 48 49 38 48 44 44 41 43 41 39 42 37 41 43 45 50 39 47 48
##  [875] 45 49 46 46 44 47 45 47 42 45 44 46 45 34 31 45 27 28 44 39 51 39 44
##  [898] 43 53 55 40 49 51 59 42 51 50 53 48 45 44 45 46 46 45 33 44 52 48 28
##  [921] 49 46 40 54 53 45 33 59 53 51 45 26 44 35 44 46 43 28 45 44 33 34 32
##  [944] 28 49 46 30 38 47 44 49 35 45 48 40 37 34 30 37 37 48 27 36 44 47 31
##  [967] 26 28 49 43 50 35 33 40 51 49 43 31 46 37 37 42 41 38 38 34 38 49 40
##  [990] 48 48 37 40 41 39 40 42 40 43 48 42 38 41 41 33 47 50 35 51 38 47 38
## [1013] 47 51 39 49 43 50 37 55 52 50 41 43 50 50 43 40 47 55 48 45 45 51 57
## [1036] 45 41 46 42 40 48 36 39 42 26 49 45 52 47 46 58 52 51 49 34 60 39 58
## [1059] 62 51 33 54 47 34 45 46 43 50 45 60 58 61 45 54 60 57 56 58 42 59 52
## [1082] 60 55 54 65 57 59 55 57 45 48 66 56 63 63 59 64 45 43 38 53 53 55 48
## [1105] 50 49 49 45 47 37 46 51 45 36 45 36 41 51 43 35 38 29 29 39 27 39 40
## [1128] 32 38 28 41 44 46 34 59 59 41 52 55 43 49 54 50 47 43 46 52 48 43 55
## [1151] 61 49 44 37 48 62 40 40 40 53 43 37 49 54 44 34 42 44 43 39 46 41 50
## [1174] 39 33 53 43 51 53 46 48 56 52 49 46 43 46 50 41 52 42 42 52 51 55 42
## [1197] 46 53 55 51 48 57 31 33 57 46 58 62 31 48 44 57 57 47 53 55 46 55 62
## [1220] 60 63 61 47 63 55 60 72 37 67 32 73 63 77 27 35 55 45 58 43 55 59 59
## [1243] 48 48 56 57 46 52 54 57 44 51 57 53 59 61 59 30 64 59 66 56 47 60 62
## [1266] 59 58 49 56 51 46 53 33 41 54 46 64 57 57 62 26 61 65 57 53 54 52 53
## [1289] 47 58 60 47 64 34 53 52 50 56 60 38 60 42 31 48 43 49 37 40 49 39 47
## [1312] 44 37 46 44 46 44 45 49 47 49 52 62 52 49 38 44 35 44 38 39 45 48 57
## [1335] 52 53 54 53 54 53 40 43 44 33 49 43 52 42 46 42 45 42 48 45 49 48 43
## [1358] 40 52 39 53 53 48 42 44 46 50 44 34 43 49 44 56 50 46 48 50 39 49 43
## [1381] 44 45 44 39 43 48 38 45 48 53 42 52 48 57 39 43 60 57 54 50 55 55 34
## [1404] 65 52 51 53 51 49 46 52 55 50 52 59 57 40 54 46 46 54 52 51 52 37 41
## [1427] 50 37 40

Question 2: les tatistiques descriptives des variable ht et circ

summary(ht)
##    Min. 1st Qu.  Median    Mean 3rd Qu.    Max. 
##   11.25   19.75   21.75   21.21   23.00   27.75
summary(circ)
##    Min. 1st Qu.  Median    Mean 3rd Qu.    Max. 
##   26.00   42.00   48.00   47.35   54.00   77.00

Question 3:

plot(eucalyptus$ht~eucalyptus$circ,xlab="circonférence",ylab="hauteur")

Question 4:

R=lm(ht~circ,data = eucalyptus)
R
## 
## Call:
## lm(formula = ht ~ circ, data = eucalyptus)
## 
## Coefficients:
## (Intercept)         circ  
##      9.0375       0.2571
summary(R)
## 
## Call:
## lm(formula = ht ~ circ, data = eucalyptus)
## 
## Residuals:
##     Min      1Q  Median      3Q     Max 
## -4.7659 -0.7802  0.0557  0.8271  3.6913 
## 
## Coefficients:
##             Estimate Std. Error t value Pr(>|t|)    
## (Intercept) 9.037476   0.179802   50.26   <2e-16 ***
## circ        0.257138   0.003738   68.79   <2e-16 ***
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
## 
## Residual standard error: 1.199 on 1427 degrees of freedom
## Multiple R-squared:  0.7683, Adjusted R-squared:  0.7682 
## F-statistic:  4732 on 1 and 1427 DF,  p-value: < 2.2e-16

Question 5:

plot(ht~circ,data = eucalyptus)

circ=seq(min(eucalyptus[,"circ"]),max(eucalyptus[,"circ"]),length=100) 
circ
##   [1] 26.00000 26.51515 27.03030 27.54545 28.06061 28.57576 29.09091
##   [8] 29.60606 30.12121 30.63636 31.15152 31.66667 32.18182 32.69697
##  [15] 33.21212 33.72727 34.24242 34.75758 35.27273 35.78788 36.30303
##  [22] 36.81818 37.33333 37.84848 38.36364 38.87879 39.39394 39.90909
##  [29] 40.42424 40.93939 41.45455 41.96970 42.48485 43.00000 43.51515
##  [36] 44.03030 44.54545 45.06061 45.57576 46.09091 46.60606 47.12121
##  [43] 47.63636 48.15152 48.66667 49.18182 49.69697 50.21212 50.72727
##  [50] 51.24242 51.75758 52.27273 52.78788 53.30303 53.81818 54.33333
##  [57] 54.84848 55.36364 55.87879 56.39394 56.90909 57.42424 57.93939
##  [64] 58.45455 58.96970 59.48485 60.00000 60.51515 61.03030 61.54545
##  [71] 62.06061 62.57576 63.09091 63.60606 64.12121 64.63636 65.15152
##  [78] 65.66667 66.18182 66.69697 67.21212 67.72727 68.24242 68.75758
##  [85] 69.27273 69.78788 70.30303 70.81818 71.33333 71.84848 72.36364
##  [92] 72.87879 73.39394 73.90909 74.42424 74.93939 75.45455 75.96970
##  [99] 76.48485 77.00000
circ1=data.frame(circ)
circ1
##         circ
## 1   26.00000
## 2   26.51515
## 3   27.03030
## 4   27.54545
## 5   28.06061
## 6   28.57576
## 7   29.09091
## 8   29.60606
## 9   30.12121
## 10  30.63636
## 11  31.15152
## 12  31.66667
## 13  32.18182
## 14  32.69697
## 15  33.21212
## 16  33.72727
## 17  34.24242
## 18  34.75758
## 19  35.27273
## 20  35.78788
## 21  36.30303
## 22  36.81818
## 23  37.33333
## 24  37.84848
## 25  38.36364
## 26  38.87879
## 27  39.39394
## 28  39.90909
## 29  40.42424
## 30  40.93939
## 31  41.45455
## 32  41.96970
## 33  42.48485
## 34  43.00000
## 35  43.51515
## 36  44.03030
## 37  44.54545
## 38  45.06061
## 39  45.57576
## 40  46.09091
## 41  46.60606
## 42  47.12121
## 43  47.63636
## 44  48.15152
## 45  48.66667
## 46  49.18182
## 47  49.69697
## 48  50.21212
## 49  50.72727
## 50  51.24242
## 51  51.75758
## 52  52.27273
## 53  52.78788
## 54  53.30303
## 55  53.81818
## 56  54.33333
## 57  54.84848
## 58  55.36364
## 59  55.87879
## 60  56.39394
## 61  56.90909
## 62  57.42424
## 63  57.93939
## 64  58.45455
## 65  58.96970
## 66  59.48485
## 67  60.00000
## 68  60.51515
## 69  61.03030
## 70  61.54545
## 71  62.06061
## 72  62.57576
## 73  63.09091
## 74  63.60606
## 75  64.12121
## 76  64.63636
## 77  65.15152
## 78  65.66667
## 79  66.18182
## 80  66.69697
## 81  67.21212
## 82  67.72727
## 83  68.24242
## 84  68.75758
## 85  69.27273
## 86  69.78788
## 87  70.30303
## 88  70.81818
## 89  71.33333
## 90  71.84848
## 91  72.36364
## 92  72.87879
## 93  73.39394
## 94  73.90909
## 95  74.42424
## 96  74.93939
## 97  75.45455
## 98  75.96970
## 99  76.48485
## 100 77.00000
IC=predict(R,new=circ1,interval = "confidence" ,level = 0.99)

Question 7:

matlines(circ1$circ,cbind(IC,IC1[,-1]) ,lty = c(1,2,2))