An astronaut is traveling in a space vehicle moving at 0.520c relative to the Earth. The astronaut measures her pulse rate at 76.0 beats per minute. Signals generated by the astronaut's pulse are radioed to the Earth when the vehicle is moving in a direction perpendicular to the line that connects the vehicle with an observer on the Earth. (Due to vehicle's path there will be no Doppler shift in the signal.)
The pulse rate measured by earth is given by the formula:
(pulse rate earth observed) = (pulse rate astronaut measured) * squareroot( 1 - v^2/c^2)
plug in velocity and pulse rate astonaut measured and you get your answer.