34.85 or 0 is not the answer for LCLc. please help

The school board is trying to evaluate a new math program introduced to second-graders in five elementary schools across the county this year. A sample of the student scores on standardized math tests in each elementary school yielded the following data: For the test errors, the c-chart with control limits that contain 99.73% of the random variation in test scores is: UCLc=errors(roundyourresponsetotwodecimalplaces). LCLc= errors (round your response to two decimal places and if your answer is negative, enter this value as 0 )