What is the probability of .87 (highlight) using extrapolation and interpoliation method then explain

Probability of finishing in 35 weeks (or less) is about 19% An entry in the table is the proportion under the curve cumulated from the negative tail. Z G(2) Z G(Z) Z G(Z) -400 0.00003 -130 0.09680 140 091924 -395 0.00004 -125 0.10565 145 092647 -390 0.00005 -120 0.11507 LEO 093319 -385 0.00006 -1.15 0.12507 155 0.93943 -380 0.00007 -110 0.13567 160 094520 -375 0.00009 -LOS 0.14686 165 0.95053 -370 -LOO 0.15866 095543 -365 0.00013 017106 175 0.95994 -360 0.00016 -0.90 0.18.406 LBO 096407 -355 0.00019 -0.85 0.19766 185 096784 -350 0.00023 190 0.97128 -345 0.00028 -0.75 0.22663 195 097441 -340 0.00034 -0,70 0.24196 2.00 097725 -335 0.000 0 -0.65 0.25785 2.05 097982 -3:30 0.00048 -0.60 0.27425 2.10 098214 -325 -0.55 0.29116 2.15 098422 -3.20 0.00069 -0.50 0.30854 2.20 0.98610 -315 0.00082 -0.45 032636 2.25 098778 -310 0.00097 -0.40 0.34458 2.30 098928 -305 -0.35 0.36317 2.35 09906: -3.00 0.00135 -0.30 0.38209 2.40 0.gg180 -2.95 0.00159 -0.25 0-40129 245 0.99286 -2.90 0.00187 -0.20 0.42074 2.50 0.99379 -285 0.00219 -0.15 0.14038 2.55 099461 -280 0.00256 -0.10 0.46017 2.60 099534 -2.75 0.00298 -0.05 0.48006 2.65 099598 -2.70 0.00347 0.00 0.50000 270 099653