On a standardized exam, the scores are normally distributed with a mean of 40 and a standard deviation of 5. Find the z-score of a person who scored 25 on the exam.

The correct solution is "3".

Step-by-step explanation:

Given that:

Mean of distribution,

Standard deviation,

Score,

Let the score in an exam be "x".

Now,

The z-score will be:

=

On putting the values, we get

=

=

=

(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.