Question

Please help!!

You roll a die as your friend records the outcomes. You rolled the die 20 times and 11 rolls were 3. Is this normal? Why or why not

Answer 1

No, this is not normal

This is a binomial distribution. Use BINS to determine if this is binomial.
B - binary?
I - independent?
N - number of trials
S - probability of success

B - yes, 3 or not a 3
I - yes, past rolls do not impact future rolls
N - 20 trials
S - prob success 1/6

Use binompdf on your calculator to find out the probability. To access, 2nd —> vars —> binompdf

Binompdf(20 (trials), 1/6 (p), 11 (x)) = 8.97x10^-5

The probability to roll a 3 11 times is .0000897. The chances are very low, making this not normal.