Exercise $6-$ Dealing with entry error

Every month, average weekday commuter boat ridership was around $4,000.$ Then, one month it jumped to

$40,000$ without warning? Unless the Olympics were happening in Boston that month $($they weren$$t$),$ this

value is certainly an error. You can assume that whoever was entering the data that month accidentally

typed $40$ instead of $4.$

$1.$ Locate the row and column of the incorrect value.

$2.$ Replace the incorrect value with $4.$

# test your ability to right this code from scratch rather than just

# filling in the blanks :$)$

$\_\_\_\_\_\_\_$

Congrats, your data is now clean and ready for analysis.

Exercise $7-$ Performing descriptive analysis

$1.$ Compute the average ridership per mode.

mbta $\%>\%$

group$\_$by$(\_\_\_\_\_\_\_)\%>\%$

summarize$($avg$\_$ridership $=\_\_\_\_\_\_\_)$

$2.$ Compute the average ridership per mode for the month of January.

mbta $\%>\%$

filter$($month $==\_\_\_\_\_)\%>\%$

group$\_$by$(\_\_\_\_\_\_\_)\%>\%$

summarize$($avg$\_$ridership $=\_\_\_\_\_\_\_)$

$6$

$3.$ Which year had the largest total ridership for the boat mode?

mbta $\%>\%$

filter$(\_\_\_\_\_\_\_)\%>\%$

group$\_$by$($year$)\%>\%$

summarize$($total$\_$riders $=\_\_\_\_($thou$\_$riders$))$

$4.$ On average, which month experiences the greatest number of passengers on the Heavy Rail mode?

# test your ability to right this code from scratch rather than just

# filling in the blanks :$)$

$\_\_\_\_\_\_\_$