$5\mathrm{.}24$ During the $1920$s and early $1930$s$,$ the NACA obtained wind tunnel data on different airfoils by testing finite wings with an aspect ratio of $6.$ These data were then "corrected" to obtain infinite$-$wing airfoil characteristics.$$ Consider such a finite wing with an area and aspect ratio of $1\mathrm{.}5$ ft$2$ and $6,$ respectively, mounted in a wind tunnel where the test$-$section flow velocity is $100$ ft$/$s at standard seal$-$level conditions.$$ When the wing is pitched to an angle of attack of $-2$o$,$ no lift is measured.$$ When the wing is pitched to an angle of attack of $10$o$,$ a lift of $17\mathrm{.}9$ lb is measured.$$ Calculate the lift slope for the airfoil $($i$.$e$.$ the infinite wing$)$ if the span effectiveness factor is $0\mathrm{.}95.$