What’s Y Y - 7= 4(x+3)

Twenty percent of drivers driving between 10 pm and 3 am are drunken drivers. In a random sample of 12 drivers driving between 1

Lesechka [4]

Answer:

(a) 0.28347

(b) 0.36909

(c) 0.0039

(d) 0.9806

Step-by-step explanation:

Given information:

n=12

p = 20% = 0.2

q = 1-p = 1-0.2 = 0.8

Binomial formula:

$P(x=r)=^nC_rp^rq^{n-r}$

(a) Exactly two will be drunken drivers.

$P(x=2)=^{12}C_{2}(0.2)^{2}(0.8)^{12-2}$

$P(x=2)=66(0.2)^{2}(0.8)^{10}$

$P(x=2)=\approx 0.28347$

Therefore, the probability that exactly two will be drunken drivers is 0.28347.

(b)Three or four will be drunken drivers.

$P(x=3\text{ or }x=4)=P(x=3)\cup P(x=4)$

$P(x=3\text{ or }x=4)=P(x=3)+P(x=4)$

Using binomial we get

$P(x=3\text{ or }x=4)=^{12}C_{3}(0.2)^{3}(0.8)^{12-3}+^{12}C_{4}(0.2)^{4}(0.8)^{12-4}$

$P(x=3\text{ or }x=4)=0.236223+0.132876$

$P(x=3\text{ or }x=4)\approx 0.369099$

Therefore, the probability that three or four will be drunken drivers is 0.3691.

(c)

At least 7 will be drunken drivers.

$P(x\geq 7)=1-P(x$

$P(x\leq 7)=1-[P(x=0)+P(x=1)+P(x=2)+P(x=3)+P(x=4)+P(x=5)+P(x=6)]$

$P(x\leq 7)=1-[0.06872+0.20616+0.28347+0.23622+0.13288+0.05315+0.0155]$

$P(x\leq 7)=1-[0.9961]$

$P(x\leq 7)=0.0039$

Therefore, the probability of at least 7 will be drunken drivers is 0.0039.

(d) At most 5 will be drunken drivers.

$P(x\leq 5)=P(x=0)+P(x=1)+P(x=2)+P(x=3)+P(x=4)+P(x=5)$

$P(x\leq 5)=0.06872+0.20616+0.28347+0.23622+0.13288+0.05315$

$P(x\leq 5)=0.9806$

Therefore, the probability of at most 5 will be drunken drivers is 0.9806.

5 0

3 years ago

gretchen and Ezia received equal scores on a test made up of multiple choice questions and an essay. Gretchen got 18 multiple ch

timurjin [86]

The multiply choice were worth 4 points.
Gretchen= 18x+19
Ezia= 15x+31

So basically you can enter any number. At first I picked 3 and then I did the math and I got 73 points for Gretchen and 76 points for Ezia.

Then I pick four and then I got 91 points for them both. This is how I got the answer:

18x+19=15x+31
18(4)+19=15(4)+31
72+19=60+31
91=91

5 0

3 years ago

Read 2 more answers

Can you help me With the equation only so I can try to answer them but if you can help me with the answer that’ll be cool too wi

Molodets [167]

Hey there,

#1 is D: 18 men and 30 women. The equation is: 12*m=48

#2 is B: Kathy drove 9 hours and Brain drove 3 hours. The equation is: 65m+55m/12=750

#3 is C: $0.86. The equation is: 2b+1h+1b+2h=8.52

#4 is B : 25 pizzas and 80 sodas. The equation is: 3*4p+5=260

:)

6 0