Pat and Kelly went hiking in the mountains. They started at 9,100 ft. They climbed 1,200 ft the first day, descended 900 ft the second day, and climbed 1,000 ft the third day. On the fourth day they descended 800 ft. What was the average altitude at which they hiked?

9,100 + 1,200 + 1,000 - 900 - 800 = ?

Divide the answer by 4.

Sorry Ms. Sue but I am confused does that include the 9100. I thought the want the average altitude should it be 925.

Take the 9100 and add or subtract each of the numbers one by one. Ex 9100 + 1200 = 10,300

9100-900=8200
9100 + 1000 = 10,100
9100 - 800 = 8300
Add all the sums and divide by 4 = 9225

To find the average altitude at which Pat and Kelly hiked, we need to calculate the total change in altitude and then divide it by the number of days.

First, let's calculate the total change in altitude. They started at 9,100 ft, climbed 1,200 ft the first day, descended 900 ft the second day, climbed 1,000 ft the third day, and descended 800 ft on the fourth day.

Change in altitude on the first day: 1,200 ft
Change in altitude on the second day: -900 ft (descended 900 ft)
Change in altitude on the third day: 1,000 ft
Change in altitude on the fourth day: -800 ft (descended 800 ft)

To get the total change, we add up these values:
Total change in altitude = 1,200 ft - 900 ft + 1,000 ft - 800 ft

Now we can calculate the average altitude:
Average altitude = (Starting altitude + Total change in altitude) / Number of days

Starting altitude = 9,100 ft
Total change in altitude = 1,200 ft - 900 ft + 1,000 ft - 800 ft
Number of days = 4

Average altitude = (9,100 ft + (1,200 ft - 900 ft + 1,000 ft - 800 ft)) / 4

Simplifying the expression inside the parentheses:
Average altitude = (9,100 ft + 1,200 ft - 900 ft + 1,000 ft - 800 ft) / 4
Average altitude = (10,500 ft) / 4

Now we can calculate the average altitude:
Average altitude = 10,500 ft / 4
Average altitude = 2,625 ft

Therefore, the average altitude at which Pat and Kelly hiked was 2,625 ft.