Find the probability of each event. Answer IN FRACTION form.

A jar contains eight black buttons and five brown buttons. If eight buttons are picked at random, what is the probability that all of them are black?

= 8/6435

Step-by-step explanation:

Number of black balls = 8

Number of Brown balls = 5

Total number of balls = 8+5 = 13

Pr (8 balls picked at random are black ) =

Number of black balls / Total number of balls.

1st Pr ( 8 balls picked are black) = 8/13

Pr (2nd random pick) = 7/12

Pr (3rd random pick) = 6/ 11

Pr (4th random pick) = 5/10

Pr (5th random pick) = 4/9

Pr (6th random pick) = 3/7

Pr (7th random pick) = 2/6

Pr (8th random pick) = 1/5

Pr (8 balls picked at random are black ) = 8/13 * 7/12 * 6/11 * 5/10 * 4/9 * 3/7 * 2/6 * 1/5

= 8/13 * 7/12 * 6/11 * 1/2 * 4/9 * 3/7 * 1/3 * 1/5

= 8/6435

But pls note, I solved it such that there wasn't a replacement after each pick.

Math is fun

1,918

step-by-step explanation:

d. 24+-0.114

step-by-step explanation:

the question requires us to calculate the approximate 95% confidence interval for the mean number of ounces of ketchup per bottle in the sample given the following statistics;

sample mean = 24

standard deviation, σ = 0.4

sample size , n = 49

the confidence interval for a population mean is calculated using the formula;

sample mean ± z-score*(σ/sqrt(n))

the z-score associated with a 95% confidence interval, from the standard normal tables, is;

1.96

substituting these values into the formula;

24 ± 1.96*(0.4/7)

= 24 ± 0.112

from the alternatives given, choice d is closest to the above expression;