• 按关注变量计算结果的均值与方差

lendingclub %>% summarise(median(loan_amnt),
                          mean(int_rate), 
                          mean(annual_inc))

lendingclub %>% group_by(verification_status) %>%
  summarise(mean(funded_amnt), 
            var(funded_amnt))

# A tibble: 3 x 3
verification_status `mean(funded_amnt)` `var(funded_amnt)`
<chr>                             <dbl>              <dbl>
1 Not Verified                   114.15          349.41953
2 Source Verified                156.14          723.53265
3 Verified                       166.08          848.54561