May I know, how to find mean and standard deviations by year and region, for the table of DealSatis, as below:

Excel data as below:

I tried using the R code but could not find mean and standard deviation.

```
# tried to read only scale and count column but could not write
Ssurvey <- read_excel("Q3.xlsx", range ="DealSatis!L4:M9") # i am looking for better way to read this table range
#as in excel: I find mean using this formula : (Scale*Count)/Count
#In finding mean in R, I could not find
total_NA_2010 <- (DSsurvey$Scale*DSsurvey$Count/DSsurvey$Count)
Warning messages:
1: Unknown or uninitialised column: 'Scale'.
2: Unknown or uninitialised column: 'Count'.
3: Unknown or uninitialised column: 'Count'.
> mean(DSsurvey$Scale)
[1] NA
Warning messages:
1: Unknown or uninitialised column: 'Scale'.
2: In mean.default(DSsurvey$Scale) :
argument is not numeric or logical: returning NA
```

```
#I got error in finding standard deviation too
SD(DSsurvey$Scale:DSsurvey$Count,na.ram=TRUE)
Error in SD(DSsurvey$Scale:DSsurvey$Count, na.ram = TRUE) :
could not find function "SD
```