# $($G Q$3$b # Use the sum$()$ and

is$.$na$()$ functions to count the number of missing values in the

points column.

sum$($

is$.$na$($wine$points$))$

# $($G Q$3$C # Use the sum$()$ and

is$.$na$()$ functions to count the number of missing values in the

price column.

sum$($

is$.$na$($wine$price$))$

# $($G Q$3$d # Use the sum$()$ and

is$.$na$()$ functions to count the number of observations that have a price.

###### Hint: Since the $!$ means "not", putting an $!$ in front of

is$.$na$()$ counts the non$-$missing values.

sum$(!$

is$.$na$($wine$price$))$

# $($G Q$4$a # Use the mean$()$ function to calculate the average points for the wines in the dataset.

mean$($wine$points$)$

# CG Q$4$b # Use the mean$()$ function to calculate the average price for the wines in the dataset. mean $($wine$price, na$.$rm$=$T$)$

# $($G Q$5$a # Use the mean$()$ function to calculate the querage points for the Napa Sonoma subregion.

###### Your code should be a single line and will use the square brackets for subsetting.. mean$($wine$points $[$wine$region$==$"Napa$-$Sonoma"$])$

# $($G Q$5$b # Use the mean$()$ function to calculate the average price for the Napa Sonoma subregionusing a single line of code.

mean$($wine$price$[$wine$region$==$"Napa$-$Sonoma"$])$

# CG Q$6$ # Now we'll practice our counting skills again.

##### The rating scale being used by these tasters orignally had $91$ as the highest possible score

##### and now goes to $100$ for exceedingly delicious wines.

##### Use the sum$()$ function on a logical vector that checks for whether points are greater than $91$ or not

##### to count the number of wine ratings with more than $91$ points.

sum$($wine$points$>91)$

# CG Q$7$a # Now we'll practice subsetting on more than one criteria.

###### Use the mean$()$ function to compute the average points for wines

###### that are chardonnay and from the Napa Sonoma sub$-$region.

mean$($wine$points $[$wine$Sonoma&wine$variety$=$"chardonnay"$],$ na$.$rm$=$T$)$

# CG Q$7$b # More practice subsetting on more than one criteria.

###### Use the mean$()$ function to compute the average price for wines that are ###### either chardonnay or are from the finger lakes sub$-$region. mean$()$

# CG Q$8$ # Use the median$()$ function to find the median price for

##### a Cabernet Sauvignon that is rated higher than $91$ points.