so at sea lvl pressure is 14.7. EVERY 30 FT DESCENT ITS INCREASES BY 14.7 PSI MORE. what is the pressure at 1000ft. my question is what would be the first term 14.7 or 29.4. AS 14.7 would be the 0 term. term 1 would be 29.4 as its 30 ft below. sea lvl would be at zero right, but my textbook says the other way around, so who's correct me or my textbook.

This isn't really an arithmetic series problem. It's a linear function, where the slope is 14.7/30

At x feet, the pressure p is

p(x) = 14.7 + (x/30)(14.7) =

so, at 1000ft, P = 14.7 + (1000/30)(14.7) = 504.7 psi

Steve thanks, but this could be solved as a arithmetic sequence problem if you do 29.4+(33.3333333-1)x14.7= which gives us 504.7 as well. It seems my textbook is wrong so that's good. Also thanks for your help! :)

In this scenario, the pressure at sea level is 14.7 psi. As you descend every 30 feet, the pressure increases by an additional 14.7 psi.

In order to determine the pressure at 1000 feet, we need to identify the correct starting point or first term.

Based on the information you provided, there seem to be two different perspectives:

1. Your perspective: According to you, the first term should be 29.4 psi because you consider the sea level as 0 psi, and the pressure increases by 14.7 psi for every 30 feet descended.

2. Textbook perspective: According to your textbook, the first term is 14.7 psi. This implies that the pressure at sea level is considered the starting point.

In this case, it seems that you and your textbook have different approaches to labeling the terms. There isn't necessarily a right or wrong perspective; it's a matter of how you choose to define the measurements.

To ensure consistency, it would be helpful to clarify with your teacher or follow the conventions set by your textbook. Understanding their specific perspective will enable you to solve problems and communicate more effectively within the context of your coursework.