Phonics is an instructional method in which children are taught to connect sounds with letters or groups of letters. A sample of 135 first graders who were learning English were asked to identify as many letter sounds as possible in a period of one minute. The average number of letter sounds identified was 34.04 with a standard deviation of 23.62

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Construct an 80%interval for the mean number of letter sounds identified in one minute. Round the answers to two decimal places. An 80%

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