i have attached the questions can u please explain what formulas you use thank you ( also we are not allowed to use excel)

An experimental psychologist believes that memory for pictures is superior to memory for words. To test this hypothesis, eight randomly selected students from an introductory psychology class view 30 slides with nouns printed on them and another group of eight randomly selected students view 30 slides with pictures of the same nouns. After completing a subsequent distractor task, participants were then given a free recall test of the pictures / words they were exposed to. Participants who were given the words recalled an average of 15.75 nouns with a standard deviation of 4.95 nouns. Participants who were given the pictures recalled an average of 20 nouns with a standard deviation of 4.24 nouns. a] Use a one-tailed test and a = .05 to determine whether memory is in fact better for pictures than it is for words [9 marks]. b] If the pooled variance for this example was 21.16, what is the effect size as determined by cohen 's d [4 marks)? c] Report and interpret the 95% condence interval [4 marks]