inputting the data for the worksheet using the TI-30XIIs

To get into the correct mode, follow these instructions.

[2nd][data]

move the underline so it is under 2-var, then press [enter].

[2nd][data]

move the underline so it so under clrdata, then press [enter].

now we enter the data.

[data]
x1 = 856.7[down]
y1 = 15.22[down]
x2 = 907.9[down]
y2 = 16.79[down]
x3 = 974.1[down]
y3 = 19.81[down]
x4 = 930.9[down]
y4 = 17.88[down]
x5 = 885.9[down]
y5 = 16.84[down]
x6 = 886.1[down]
y6 = 16.87[down]
x7 = 926.8[down]
y7 = 17.48[down]
x8 = 928.4[down]
y8 = 17.34[down]
x9 = 802.9[down]
y9 = 12.22[down]
x10 = 834.8[down]
y10 = 11.16[down]
x11 = 734.3[down]
y11 = 9.37[down]
x12 = 816.3[down]
y12 = 10.26[down]
x13=[statvar]

The numbers you need are
rx,y = .946053079... ~= .946 (Above the 99% threshold of .708)
a = 0.048098608... ~= .0481
b = -26.92322636... ~= -26.9232

So the formula to find the points on the line is yp = ax + b if you use the exact values and if using the approximation, yp = .0481x - 26.9232.

Answer for both versions to the nearest penny in the comments.