Assume that when adults with smartphones are randomly selected, 56% use them in meetings or classes. If 11 adult smartphone users are randomly selected, find the probability that fewer than 3 of them use their smartphones in meetings or classes.

Step-by-step explanation:

Use binomial probability:

P = nCr pʳ qⁿ⁻ʳ

where n is the number of trials,

r is the number of successes,

p is the probability of success,

and q is the probability of failure (1−p).

Here, n = 11, p = 0.56, q = 0.44, and r = 0, 1, or 2.

P = ₁₁C₀ (0.56)⁰ (0.44)¹¹ + ₁₁C₁ (0.56)¹ (0.44)¹⁰ + ₁₁C₂ (0.56)² (0.44)⁹

P = (0.44)¹¹ + 11 (0.56) (0.44)¹⁰ + 55 (0.56)² (0.44)⁹

P ≈ 0.0125

29 is the correct answer

step-by-step explanation:

answer: c, the green line

step-by-step explanation:

there is no black line, eliminate b.

simple interest implies periodic payments, but the red line shows no payments, eliminate d.

simple interest has equal payments. if paid say every day, the graph is about a straight line (actually a stairstep).

the yellow line is not straight, eliminate a.

check: the green line is straight, answer is c.

simple interest with positive interest rate gives a straight line sloping up to the right. green line:

g(t) = $100 + ($200-$100) ÷ (20 years) × (t years)

= $100 + (4%/year) × ($100)(t years)

incidentally, the yellow line curving upward represents continuously compounded interest

y = $100 × 2^(t years / (14 assuming the yellow line hits $200 at 14 years. 2^0 is 1, so y(0) = $100; 2^(14/14) is 2, so y(14) = $200.