7. a recent medical survey reported that 45% of the respondents felt that the doctor explained their condition in a sufficient manner. assuming that this poll reflects all the patients, find the probability that for 12 patients:
a. four or more agree
b. no more than 8 agreed

(a) 0.8655

(b)0.8655

Step-by-step explanation:

X is the number of respodents who agree

P(x ≥4), n=12, p=0.45

P(x ≥4)=1-P(x<4)

P(x<4)=P(0 ≤x<4)= P(0 ≤x≤3)=P(x=0,1,2,3)=P(x=0)+P(x=1)+P(x=2)+P(x=3)

P(x ≥4)=1-P(x<4)=1-0.134468=0.8655319

(b)

Y represent those who agree

P(Y≤8), n=12, p=0.45

P(Y≤8)=1-P(Y>8)

P(Y>8)=P(8<Y≤12)=P(9≤Y≤12)=P(Y=9,10,11,12)

Total =0.134468

P=1-0.134468=0.8655319

set each factor equal to 0

4x-3 = 0

2x-1 = 0

solve for x.

4x-3=0

4x=3

x= 3/4

solve for x. 

2x-1= 0

2x= 1

x= 1/2

eventually after a few more steps, your answer should be 1/2 is less than or equal to x and 3/4 is greater than or equal to x

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.