Thirty workers in a factory were polled to determine their preferred room temperature. Their average preferred temperature was 72.0°F. Assuming that the preferred temperature of the entire factory of workers is normally distributed with a standard deviation of 3.0°F, the upper and lower 95% confidence levels for the true preferred temperature for all workers are:

the law of definite proportions states samples of a compound will always contain the same proportion of elements by mass. in other words, a given compound will always contain the same elements in the same proportions by mass.the law of multiple proportions states when two elements combine with each other to form more than one compound, then the weights of one element that combine with a fixed weight of the other are in a ratio of small whole numbers.