Candidates for promotion at a city police department are required to take a written aptitude test. Scores on this test are normally distributed with a mean of 230 and a standard deviation of 50. A random sample of 9 test scores was taken. (a)What is the standard error of the sample mean score

Asix-sided die of unknown bias is rolled 20 times, and the number 3 comes up 6 times. in the next three rounds (the die is rolled 20 times in each round), the number 3 comes up 6 times, 5 times, and 7 times. the experimental probability of rolling a 3 is 10 %, which is approximately % more than its theoretical probability. (round off your answers to the nearest integer.)