HELP PLEASE!!

A multiple-choice test has 15 questions. Each question has 4 possible responses, so the
probability is 0.25 for guessing right. Suppose you randomly guess for all 15 questions.
Let X = the number of correct responses.

1. Calculate the mean of X. Interpret the mean in context.

2. Calculate the standard deviation of X. Interpret the mean in context.

1^3 + 2^3 + 3^3 +4^3 = (1+2+3+4)^2

step-by-step explanation:

i am only able to answer the first part. i am not sure about the second part. sorry

(a) {a₁, a₁r, a₁r², … a₁rⁿ⁻¹, …}

(b) $59 398

step-by-step explanation:

(a) the annual sequence of profits

aₙ = a₁rⁿ⁻¹

the model for the sequence of profits is {a₁, a₁r, a₁r², … a₁rⁿ⁻¹, …} .

(b) profit after 15 yr

  a₁ = $ 30 000

  r = 1.05

a₁₅ = 30 000 × 1.05¹⁴

a₁₅ = 30 000 × 1.979 93

a₁₅ = $59 398

the profit in year 15 will be $59 398.

1332.

this is because to get from 333 to 999 you multiply by 3, and you should do the same to the number of hours.

therefore you would do 444*3=1332