What is a method to predict an earthquake?

The force acting on a beam was measured under the same operating conditions and a sample of 5 data points was collected. this process was repeated by 3 observers. the pooled standard deviations of these 3 data sets was 1.21. determine the true mean force using all pooled data (with a 95% probability). the result should look like this: true mean = mean +/- margin of error

Blank liquids and gases exert a buoyant force on objects placed in them

If angle "a" is 25°, angle "b" is: a) equal to angle c b) less than angle c c) greater than angle c