Question

A spinner has two colored regions — purple and orange — and is divided in such a way so that the probability that the spinner lands on purple is 0.9. Suppose we spin the spinner 12 times and let X = the number of times it lands in the purple region.

Calculate the mean and standard deviation of X. Round to 4 decimal places, when necessary.

μx =

σx =

Answer 1

10.8

1.0392

Explanation:

for the shape of the probability histogran it is D) Skewed left

Answer 2

The answer is "32 and 4.6648".

Explanation:

binomial distribution of x

probability of sucess
`(P)=32\%=0.32`

randomly selected number by giraffes
`n=100`

now

`\mu_x=np\\\\`

`=(100)(0.32)\\\\=32\\\\`

`\Sigma_x=√(np(1-p))`

`=√(100(0.32)(1-0.32))\\\\=√(21.76)\\\\= 4.664761\\\\=4.6648`