Please Help!! (will give brainliest for best answer)

Which statements are true about each person’s work? Check all that apply.
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Sam claims that cos x =sin y if x and y are congruent angels. is sam correct ?

Scores on a university exam are normally distributed with a mean of 78 and a standard deviation of 8. the professor teaching the class declares that a score of 70 or higher is required for a grade of at least “c.” using the 68-95-99.7 rule, what percentage of students failed to earn a grade of at least “c”?

C. using a standard deck of 52 cards, the probability of selecting a 4 of diamonds or a 4 of hearts is an example of a mutually exclusive event. true of false