Answer
$P(x<10)=0.830$
Work Step by Step
$P(x<10)=P(0)+P(1)+P(2)+P(3)+P(4)+P(5)+P(6)+P(7)+P(8)+P(9)=\frac{7^{0}}{0!}e^{-7}+\frac{7^{1}}{1!}e^{-7}+\frac{7^{2}}{2!}e^{-7}+\frac{7^{3}}{3!}e^{-7}+\frac{7^{4}}{4!}e^{-7}+\frac{7^{5}}{5!}e^{-7}+\frac{7^{6}}{6!}e^{-7}+\frac{7^{7}}{7!}e^{-7}+\frac{7^{8}}{8!}e^{-7}+\frac{7^{9}}{9!}e^{-7}=\frac{1}{1}e^{-7}+\frac{7}{1}e^{-7}+\frac{49}{2}e^{-7}+\frac{343}{6}e^{-7}+\frac{2401}{24}e^{-7}+\frac{16807}{120}e^{-7}+\frac{117649}{720}e^{-7}+\frac{823543}{5040}e^{-7}+\frac{5764801}{40320}e^{-7}+\frac{40353607}{362880}e^{-7}=0.830$
