2. A biased die is thrown fifteen times and the number of threes seen is four. If the die
is thrown a further six-time, find the
variance of the number of threes and
standard deviation.

Write the point-slope form of the line passing through (2, -12) and parallel to y=3x.

Look at the figure below: triangle abc is a right triangle with angle abc equal to 90 degrees. the length of ac is 5 units and the length of ab is 4 units. d is a point above c. triangle adc is a right triangle with angle dac equal to 90 degrees and dc parallel to ab. what is the length, in units, of segment cd?

Look at the chart showing the results of a baseball player at bat. which is the probability of getting a hit?