library(dplyr)
data(survey_data)
# Total score across items
survey_data <- survey_data %>%
mutate(total = row_sums(., trust_government, trust_media, trust_science))
# With min_valid (like SPSS SUM.3)
survey_data <- survey_data %>%
mutate(total = row_sums(., trust_government, trust_media,
trust_science, min_valid = 3))
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