Consider the following regression analysis output:

SUMMARY OUTPUT

Regression Statistics

Multiple R $0\mathrm{.}9999$

R Square $0\mathrm{.}9999$

Adjusted R Square $0\mathrm{.}9999$

Standard Error $0\mathrm{.}0650$

Observations $55\mathrm{.}0000$

ANOVA

df SS MS F Significance F

Regression $2\mathrm{.}00002,164\mathrm{.}37851,082\mathrm{.}1892255,948\mathrm{.}25260\mathrm{.}0000$

Residual $52\mathrm{.}00000\mathrm{.}21990\mathrm{.}0042$

Total $54\mathrm{.}00002,164\mathrm{.}5983$

Coefficients Standard Error t Stat P$-$value Lower $95\%$ Upper $95\%$

Intercept $100\mathrm{.}04810\mathrm{.}1716583\mathrm{.}11170\mathrm{.}000099\mathrm{.}7038100\mathrm{.}3924$

X Variable $10\mathrm{.}44910\mathrm{.}0007601\mathrm{.}87310\mathrm{.}00000\mathrm{.}44760\mathrm{.}4506$

X Variable $20\mathrm{.}25020\mathrm{.}0006388\mathrm{.}35490\mathrm{.}00000\mathrm{.}24890\mathrm{.}2515$

What is the number of observations?