a.

library(haven)
library(readxl)

TUR <- read_sav("D:/OLC_733/hafta 1 odev/BSATURM6.sav") 
bilgi <- read_excel("D:/OLC_733/hafta 1 odev/T15_G8_ItemInformation.xlsx")

b.

library(dplyr)
## 
## Attaching package: 'dplyr'
## The following objects are masked from 'package:stats':
## 
##     filter, lag
## The following objects are masked from 'package:base':
## 
##     intersect, setdiff, setequal, union
TUR_sec <- TUR %>%
  select(IDCNTRY, IDSTUD, IDBOOK, starts_with("M0"))
dim(TUR_sec)
## [1] 6079  228

c.

TUR_sec <- TUR_sec %>%
  select(-any_of(c("M062345B", "M062345BA", "M062345BB", "M062345BC", 
                   "M062345BD", "M062342", "M062048", "M062048A", 
                   "M062048B", "M062048C")))

d.

bilgi <- bilgi %>%
  filter(!(`Item ID` %in% c("M062345B", "M062345BA", "M062345BB", "M062345BC", 
                            "M062345BD", "M062342", "M062048", "M062048A", 
                            "M062048B", "M062048C")))

e.

donusmus <- TUR_sec

donusmus <- donusmus %>%
  mutate(across(starts_with("Item"), 
                ~ifelse(Item_Type == "Multiple Choice" & 
                          . == match(Key, c("A", "B", "C", "D")), 1, 0)))

donusmus <- donusmus %>%
  mutate(across(starts_with("Item"), 
                ~ifelse(Item_Type == "Partial Credit", 
                        ifelse(Maximum_Points == 10, 1, 0), 
                        .)))
"Hocam odevi 75 dk civarında yaptım."