A time study of a factory worker has revealed an average observed time of 3.00 minutes, with a standard deviation of 1.00 minute These figures were based on a sample of 45 observations. Assume that the firm wants to be 90% confident that the standard time is within 5 % of the true value. (Round all intermediate calculations to two decimal places before proceeding with further calculations.)

Based on the given information and the given confidence level and accuracy level, the number of observations that would be necessary for the time study =

observations (round your response up to the next whole number).