Ashipment of marbles with a mean diameter of 27 mm and a standard deviation of 0.15 mm is normally distributed. by how many standard deviations does a marble with a diameter of 26.85 mm differ from the mean?

This could be solved by calculating the z-score. Its definition is the number of standard deviations from the mean a data point is. The formula is,

Z =║Data point – Mean║ / Std. dev.

Z = ║26.85 mm – 27 mm║ / 0.15

Z = 1

blue marble is 15 times out of 50 = 15/50 reduces to 3/10

landing on tails is 24 out of 50 = 24/50 reduces to 12/25

to find the probability of both multiply together:

3/10 x 12/25 = 3 x 12 / 10 x 25 = 36/250

if you multiplied the numerator and denominator by 10 you get 360/2500.

the answer is 360/2500

answer:

c. the third graph