Use T-test] The average grade of grade 7 students in English course was recorded at 89. An English teacher wanted to know if this has changed. Thirty (30) grade 7 students who were randomly selected showed an average grade of 80 in English course with standard deviation of 2.25. Is there improvement on their English course grades? At a 0.05 level of significance, is the average grade of grade 7 students in English course better than 89?

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