Use the continuity correction and describe the region of the normal distribution that corresponds to the indicated probability. for example, the probability of "more than 20 defective items" corresponds to the area of the normal curve described with this "the area to the right of 20.5." the probability of at least 13 adult males on an elevator? the probablity is the area under the normal curve to left/right of ?

We let x be the original amount of the food such that adding 15% gratuity will sum up to $213.90.
                          x + 0.15x = 213.90
The value of x from the equation is 186.
The value of the 15% gratuity is 27.90
Adding $20 to the gratuity will give us $47.90.

Now, divide this sum by the original amount and divide the sum by 186.
                         = ($47.90/$186) x 100% = 25.75%