Question One

1.) Attach(mtcars)
2.) Sort by ascending MPG
3.) Sort by descending CYL
4.) Sort by both

attach(mtcars)
mtcars_df_mpg <- mtcars[order(mpg),]
mtcars_df_mpg
##                      mpg cyl  disp  hp drat    wt  qsec vs am gear carb
## Cadillac Fleetwood  10.4   8 472.0 205 2.93 5.250 17.98  0  0    3    4
## Lincoln Continental 10.4   8 460.0 215 3.00 5.424 17.82  0  0    3    4
## Camaro Z28          13.3   8 350.0 245 3.73 3.840 15.41  0  0    3    4
## Duster 360          14.3   8 360.0 245 3.21 3.570 15.84  0  0    3    4
## Chrysler Imperial   14.7   8 440.0 230 3.23 5.345 17.42  0  0    3    4
## Maserati Bora       15.0   8 301.0 335 3.54 3.570 14.60  0  1    5    8
## Merc 450SLC         15.2   8 275.8 180 3.07 3.780 18.00  0  0    3    3
## AMC Javelin         15.2   8 304.0 150 3.15 3.435 17.30  0  0    3    2
## Dodge Challenger    15.5   8 318.0 150 2.76 3.520 16.87  0  0    3    2
## Ford Pantera L      15.8   8 351.0 264 4.22 3.170 14.50  0  1    5    4
## Merc 450SE          16.4   8 275.8 180 3.07 4.070 17.40  0  0    3    3
## Merc 450SL          17.3   8 275.8 180 3.07 3.730 17.60  0  0    3    3
## Merc 280C           17.8   6 167.6 123 3.92 3.440 18.90  1  0    4    4
## Valiant             18.1   6 225.0 105 2.76 3.460 20.22  1  0    3    1
## Hornet Sportabout   18.7   8 360.0 175 3.15 3.440 17.02  0  0    3    2
## Merc 280            19.2   6 167.6 123 3.92 3.440 18.30  1  0    4    4
## Pontiac Firebird    19.2   8 400.0 175 3.08 3.845 17.05  0  0    3    2
## Ferrari Dino        19.7   6 145.0 175 3.62 2.770 15.50  0  1    5    6
## Mazda RX4           21.0   6 160.0 110 3.90 2.620 16.46  0  1    4    4
## Mazda RX4 Wag       21.0   6 160.0 110 3.90 2.875 17.02  0  1    4    4
## Hornet 4 Drive      21.4   6 258.0 110 3.08 3.215 19.44  1  0    3    1
## Volvo 142E          21.4   4 121.0 109 4.11 2.780 18.60  1  1    4    2
## Toyota Corona       21.5   4 120.1  97 3.70 2.465 20.01  1  0    3    1
## Datsun 710          22.8   4 108.0  93 3.85 2.320 18.61  1  1    4    1
## Merc 230            22.8   4 140.8  95 3.92 3.150 22.90  1  0    4    2
## Merc 240D           24.4   4 146.7  62 3.69 3.190 20.00  1  0    4    2
## Porsche 914-2       26.0   4 120.3  91 4.43 2.140 16.70  0  1    5    2
## Fiat X1-9           27.3   4  79.0  66 4.08 1.935 18.90  1  1    4    1
## Honda Civic         30.4   4  75.7  52 4.93 1.615 18.52  1  1    4    2
## Lotus Europa        30.4   4  95.1 113 3.77 1.513 16.90  1  1    5    2
## Fiat 128            32.4   4  78.7  66 4.08 2.200 19.47  1  1    4    1
## Toyota Corolla      33.9   4  71.1  65 4.22 1.835 19.90  1  1    4    1
mtcars_df_cyl <- mtcars[order(-cyl),] 
mtcars_df_cyl 
##                      mpg cyl  disp  hp drat    wt  qsec vs am gear carb
## Hornet Sportabout   18.7   8 360.0 175 3.15 3.440 17.02  0  0    3    2
## Duster 360          14.3   8 360.0 245 3.21 3.570 15.84  0  0    3    4
## Merc 450SE          16.4   8 275.8 180 3.07 4.070 17.40  0  0    3    3
## Merc 450SL          17.3   8 275.8 180 3.07 3.730 17.60  0  0    3    3
## Merc 450SLC         15.2   8 275.8 180 3.07 3.780 18.00  0  0    3    3
## Cadillac Fleetwood  10.4   8 472.0 205 2.93 5.250 17.98  0  0    3    4
## Lincoln Continental 10.4   8 460.0 215 3.00 5.424 17.82  0  0    3    4
## Chrysler Imperial   14.7   8 440.0 230 3.23 5.345 17.42  0  0    3    4
## Dodge Challenger    15.5   8 318.0 150 2.76 3.520 16.87  0  0    3    2
## AMC Javelin         15.2   8 304.0 150 3.15 3.435 17.30  0  0    3    2
## Camaro Z28          13.3   8 350.0 245 3.73 3.840 15.41  0  0    3    4
## Pontiac Firebird    19.2   8 400.0 175 3.08 3.845 17.05  0  0    3    2
## Ford Pantera L      15.8   8 351.0 264 4.22 3.170 14.50  0  1    5    4
## Maserati Bora       15.0   8 301.0 335 3.54 3.570 14.60  0  1    5    8
## Mazda RX4           21.0   6 160.0 110 3.90 2.620 16.46  0  1    4    4
## Mazda RX4 Wag       21.0   6 160.0 110 3.90 2.875 17.02  0  1    4    4
## Hornet 4 Drive      21.4   6 258.0 110 3.08 3.215 19.44  1  0    3    1
## Valiant             18.1   6 225.0 105 2.76 3.460 20.22  1  0    3    1
## Merc 280            19.2   6 167.6 123 3.92 3.440 18.30  1  0    4    4
## Merc 280C           17.8   6 167.6 123 3.92 3.440 18.90  1  0    4    4
## Ferrari Dino        19.7   6 145.0 175 3.62 2.770 15.50  0  1    5    6
## Datsun 710          22.8   4 108.0  93 3.85 2.320 18.61  1  1    4    1
## Merc 240D           24.4   4 146.7  62 3.69 3.190 20.00  1  0    4    2
## Merc 230            22.8   4 140.8  95 3.92 3.150 22.90  1  0    4    2
## Fiat 128            32.4   4  78.7  66 4.08 2.200 19.47  1  1    4    1
## Honda Civic         30.4   4  75.7  52 4.93 1.615 18.52  1  1    4    2
## Toyota Corolla      33.9   4  71.1  65 4.22 1.835 19.90  1  1    4    1
## Toyota Corona       21.5   4 120.1  97 3.70 2.465 20.01  1  0    3    1
## Fiat X1-9           27.3   4  79.0  66 4.08 1.935 18.90  1  1    4    1
## Porsche 914-2       26.0   4 120.3  91 4.43 2.140 16.70  0  1    5    2
## Lotus Europa        30.4   4  95.1 113 3.77 1.513 16.90  1  1    5    2
## Volvo 142E          21.4   4 121.0 109 4.11 2.780 18.60  1  1    4    2
mtcars_df_mpg_cyl <- mtcars[order(mpg,-cyl),] 
mtcars_df_mpg_cyl 
##                      mpg cyl  disp  hp drat    wt  qsec vs am gear carb
## Cadillac Fleetwood  10.4   8 472.0 205 2.93 5.250 17.98  0  0    3    4
## Lincoln Continental 10.4   8 460.0 215 3.00 5.424 17.82  0  0    3    4
## Camaro Z28          13.3   8 350.0 245 3.73 3.840 15.41  0  0    3    4
## Duster 360          14.3   8 360.0 245 3.21 3.570 15.84  0  0    3    4
## Chrysler Imperial   14.7   8 440.0 230 3.23 5.345 17.42  0  0    3    4
## Maserati Bora       15.0   8 301.0 335 3.54 3.570 14.60  0  1    5    8
## Merc 450SLC         15.2   8 275.8 180 3.07 3.780 18.00  0  0    3    3
## AMC Javelin         15.2   8 304.0 150 3.15 3.435 17.30  0  0    3    2
## Dodge Challenger    15.5   8 318.0 150 2.76 3.520 16.87  0  0    3    2
## Ford Pantera L      15.8   8 351.0 264 4.22 3.170 14.50  0  1    5    4
## Merc 450SE          16.4   8 275.8 180 3.07 4.070 17.40  0  0    3    3
## Merc 450SL          17.3   8 275.8 180 3.07 3.730 17.60  0  0    3    3
## Merc 280C           17.8   6 167.6 123 3.92 3.440 18.90  1  0    4    4
## Valiant             18.1   6 225.0 105 2.76 3.460 20.22  1  0    3    1
## Hornet Sportabout   18.7   8 360.0 175 3.15 3.440 17.02  0  0    3    2
## Pontiac Firebird    19.2   8 400.0 175 3.08 3.845 17.05  0  0    3    2
## Merc 280            19.2   6 167.6 123 3.92 3.440 18.30  1  0    4    4
## Ferrari Dino        19.7   6 145.0 175 3.62 2.770 15.50  0  1    5    6
## Mazda RX4           21.0   6 160.0 110 3.90 2.620 16.46  0  1    4    4
## Mazda RX4 Wag       21.0   6 160.0 110 3.90 2.875 17.02  0  1    4    4
## Hornet 4 Drive      21.4   6 258.0 110 3.08 3.215 19.44  1  0    3    1
## Volvo 142E          21.4   4 121.0 109 4.11 2.780 18.60  1  1    4    2
## Toyota Corona       21.5   4 120.1  97 3.70 2.465 20.01  1  0    3    1
## Datsun 710          22.8   4 108.0  93 3.85 2.320 18.61  1  1    4    1
## Merc 230            22.8   4 140.8  95 3.92 3.150 22.90  1  0    4    2
## Merc 240D           24.4   4 146.7  62 3.69 3.190 20.00  1  0    4    2
## Porsche 914-2       26.0   4 120.3  91 4.43 2.140 16.70  0  1    5    2
## Fiat X1-9           27.3   4  79.0  66 4.08 1.935 18.90  1  1    4    1
## Honda Civic         30.4   4  75.7  52 4.93 1.615 18.52  1  1    4    2
## Lotus Europa        30.4   4  95.1 113 3.77 1.513 16.90  1  1    5    2
## Fiat 128            32.4   4  78.7  66 4.08 2.200 19.47  1  1    4    1
## Toyota Corolla      33.9   4  71.1  65 4.22 1.835 19.90  1  1    4    1
detach(mtcars)

Question Two

1.) Attach(mtcars)
2.) Find value of Chrysler Imperial HP
3.) Sort by ascending MPG
4.) Select cars whose HP is greater then Chrysler Imperial

attach(mtcars)
rownames(mtcars)
##  [1] "Mazda RX4"           "Mazda RX4 Wag"       "Datsun 710"         
##  [4] "Hornet 4 Drive"      "Hornet Sportabout"   "Valiant"            
##  [7] "Duster 360"          "Merc 240D"           "Merc 230"           
## [10] "Merc 280"            "Merc 280C"           "Merc 450SE"         
## [13] "Merc 450SL"          "Merc 450SLC"         "Cadillac Fleetwood" 
## [16] "Lincoln Continental" "Chrysler Imperial"   "Fiat 128"           
## [19] "Honda Civic"         "Toyota Corolla"      "Toyota Corona"      
## [22] "Dodge Challenger"    "AMC Javelin"         "Camaro Z28"         
## [25] "Pontiac Firebird"    "Fiat X1-9"           "Porsche 914-2"      
## [28] "Lotus Europa"        "Ford Pantera L"      "Ferrari Dino"       
## [31] "Maserati Bora"       "Volvo 142E"
CI_row <- mtcars[rownames(mtcars) == "Chrysler Imperial",]
CI_row
##                    mpg cyl disp  hp drat    wt  qsec vs am gear carb
## Chrysler Imperial 14.7   8  440 230 3.23 5.345 17.42  0  0    3    4
CI_value <- CI_row$hp
CI_value
## [1] 230
mtcars_CI_mpg <- mtcars[order(mpg),]
mtcars_CIsubset <- mtcars_CI_mpg[(mtcars_CI_mpg$hp > CI_value),]
mtcars_CIsubset <- mtcars_CIsubset[complete.cases(mtcars_CIsubset),]
mtcars_CIsubset
##                 mpg cyl disp  hp drat   wt  qsec vs am gear carb
## Camaro Z28     13.3   8  350 245 3.73 3.84 15.41  0  0    3    4
## Duster 360     14.3   8  360 245 3.21 3.57 15.84  0  0    3    4
## Maserati Bora  15.0   8  301 335 3.54 3.57 14.60  0  1    5    8
## Ford Pantera L 15.8   8  351 264 4.22 3.17 14.50  0  1    5    4

Question Three

1.) Create a For Loop that calculates the squared values for 1 to 25.

q3_for_lst <- c()
for (i in seq(1, 25, by=1)) {
  q3_for_lst[[i]] <- i*i
}
q3_for_matrix <- as.matrix(q3_for_lst)
print(q3_for_matrix)
##       [,1]
##  [1,] 1   
##  [2,] 4   
##  [3,] 9   
##  [4,] 16  
##  [5,] 25  
##  [6,] 36  
##  [7,] 49  
##  [8,] 64  
##  [9,] 81  
## [10,] 100 
## [11,] 121 
## [12,] 144 
## [13,] 169 
## [14,] 196 
## [15,] 225 
## [16,] 256 
## [17,] 289 
## [18,] 324 
## [19,] 361 
## [20,] 400 
## [21,] 441 
## [22,] 484 
## [23,] 529 
## [24,] 576 
## [25,] 625

Question Four

1.) Create a For Loop that calculates the 50 elements from Fibonacci Series [1,1,2,3,5,8,13,21,….]

start.time <- Sys.time() 

q4_for_lst <- c(1,2)
for (i in seq(3, 50, by=1)) {
  q4_for_lst[[i]] <- q4_for_lst[i-2] + q4_for_lst[i-1]
}
q4_for_matrix <- as.matrix(q4_for_lst)
print(q4_for_matrix)
##              [,1]
##  [1,]           1
##  [2,]           2
##  [3,]           3
##  [4,]           5
##  [5,]           8
##  [6,]          13
##  [7,]          21
##  [8,]          34
##  [9,]          55
## [10,]          89
## [11,]         144
## [12,]         233
## [13,]         377
## [14,]         610
## [15,]         987
## [16,]        1597
## [17,]        2584
## [18,]        4181
## [19,]        6765
## [20,]       10946
## [21,]       17711
## [22,]       28657
## [23,]       46368
## [24,]       75025
## [25,]      121393
## [26,]      196418
## [27,]      317811
## [28,]      514229
## [29,]      832040
## [30,]     1346269
## [31,]     2178309
## [32,]     3524578
## [33,]     5702887
## [34,]     9227465
## [35,]    14930352
## [36,]    24157817
## [37,]    39088169
## [38,]    63245986
## [39,]   102334155
## [40,]   165580141
## [41,]   267914296
## [42,]   433494437
## [43,]   701408733
## [44,]  1134903170
## [45,]  1836311903
## [46,]  2971215073
## [47,]  4807526976
## [48,]  7778742049
## [49,] 12586269025
## [50,] 20365011074
end.time <- Sys.time() 
time.taken <- end.time - start.time 
time.taken
## Time difference of 0.008983135 secs

Question Five

You bought a house at price of $700K. If the interest to real estate market in the area increases and the estimated price of house goes above 750K, you may want to sell it. Otherwise, you will keep it. You will generate a random price between 600K and 800K for each quarter as a proxy for the interest to your house (The price can fluctuate between -100K to +100K around 700K after each quarter)

1.) Design a while loop and show how many quarters (loops) will it take to sell the house. Hint: There is no specific value for the answer since we generate random values with sample(x, size, replace = FALSE, prob = NULL) in each loop.

While Loop (while home price < $750K)
1 Generate random home price between parameters
2 Check if home price is over $750k
3 If yes, then break while loop sell and print message including the sale price and profit!
4 If no, continue in loop and start at 1

Using runif() method below
Home_Price <- 1
Sales_Quarters <-0
#Create the loop
while (Home_Price <= 750000){
  Home_Price <- runif(1, min=600000, max=800000)
  Sales_Quarters <- Sales_Quarters + 1
}
Home_Price <- paste('$',formatC(Home_Price, big.mark = ',', format = 'f', digits = 2L))

Congrats! Your sold for $ 765,080.02, and it only took you 5 Quarters

Using sample() method below
Home_Price <- 1
Sales_Quarters <-0
#Create the loop
while (Home_Price <= 750000){
  Home_Price <- sample(600000:800000, 1,replace = FALSE, prob = NULL)
  Sales_Quarters <- Sales_Quarters + 1
}
Home_Price <- paste('$',formatC(Home_Price, big.mark = ',', format = 'f', digits = 2L))

Congrats! Your sold for $ 773,490.00, and it only took you 1 Quarters