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3 years ago

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Mary jogged 2 7/8 miles per hour for 2 2/3 hours. During 1/3 of her jogging time, she was jogging in the rain. How many miles d

id she jog in the rain?

1 answer:

alexira [117]3 years ago

4 0

Answer:

C

Step-by-step explanation:

QRRT

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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

Quick plz help asap marking brainliest for first answer as long as you include steps !!!

Akimi4 [234]

Answer:

a=2.48

c=9.52

Step-by-step explanation:

a+c=12

4a+7.5c=72.5 Given

a+c=12

-4a-7.5c=-72.5 multiply the equation by negative 1

-3a-6.5c=-60.5 simplify

-3a=-60.5+6.5c add 6.5c to both sides

a=-20.17+2.17c divide it by 3

now you would take that equation and plug it into an equation you already have since you have something to plug in for a, the easiest one to do is a+c=12

(-20.17+2.17c)+c=12 plug in the equation

-20.17+3.17c=12 simplify by solving for c

3.17c=30.17 add 20.17 to both sides

c=9.52 divide both sides by 3.17

now since you have found c, you can plug it in to you equation to solve for a now (use the ones from the second step). I am using the equation a+c=12.

a+9.52=12 plug in the variable and solve for a

a=2.48 subtract 9.52 to both sides

a=2.48

c=9.52

7 0

3 years ago

Help please? It’s math.

Umnica [9.8K]

Answer:
X = 7/5
when the value of x is 7/5 the equation will be true
Step-by-step explanation:
To fine the value of x that makes the equation true, we equate the expression to zero to find the value of x.
Check attachment for processes
Therefore when the value of x is 7/5 the equation will be true

8 0

3 years ago

A retangle has an area of 30 square meters and a perimeter of 34 meters what are the dimensions of the retangle

s344n2d4d5 [400]

Answer: Length = 15 meters

Width = 2 meters

Step-by-step explanation:

Perimeter of a rectangle = 2l + 2w

Area of a rectangle = l × w

where l = length

w = width

Therefore,

2l + 2w = 34 ...... i

l × w = 30 ........ ii

From equation i

2l + 2w = 34

Divide through by 2.

l + w = 17 ...... iii

Then, l = 17 - w ........ iv

Put equation iv into ii

l × w = 30

(17 - w) × w = 30

17w - w² = 30

w² - 17w + 30 = 0

w² - 15w - 2w + 30 = 0

w(w - 15) - 2(w - 15) = 0

(w - 2) = 0

w = 0 + 2 = 2

w - 15 = 0

w = 0 + 15 = 15

Length = 15 meters

Width = 2 meters

6 0

3 years ago

CAN SOME ONE PLZ HELP I NEED HELP

Romashka [77]

Answer:

9

Step-by-step explanation:

5 0

2 years ago

Read 2 more answers