Here is my problem:In the absence of turbulent mixing, the partial pressure of each

constituent of air would fall off with height above sea level in

Earth's atmosphere as $P_i=P_i^0{e}^{-M_{i}g\frac{z}{RT}}$ where $P_i$ is the partial

pressure at the height $z,P_i^0$ is the partial pressure of component $i$ at

sea level, $g$ is the acceleration of gravity, $R$ is the gas constant, $T$ is

the absolute temperature, and $M_i$ is the molecular mass of the gas.

As a result of turbulent mixing, the composition of Earth's

atmosphere is constant below an altitude of $100km,$ but the total

pressure decreases with altitude as $P=P^0{e}^{-M_{\text{a}\text{v}\text{e}}g\frac{z}{RT}}$ where

$M_{\text{a}\text{v}\text{e}}$ is the mean molecular weight of air. At sea level,

$x_{N_2}=0\mathrm{.}78084$ and $x_{He}=0\mathrm{.}00000524$ and $T=300.K.$Calculate the total pressure at $11\mathrm{.}5km,$ assuming a mean molecular mass of $28\mathrm{.}9g*mo{l}^{-1}$ and that $T=300.K$ throughout this altitude range.

Express the total pressure in pascals to three significant figures.

$P_{\text{t}\text{o}\text{t}}=$

Incorrect; Try Again; $5$ attempts remaining${10}^5*e^{(-28\mathrm{.}9*{10}^{-3}*9\mathrm{.}81*\frac{11\mathrm{.}5*{10}^3}{8\mathrm{.}314*300})},=27058\mathrm{.}36345$