Answer:
0.49
Step-by-step explanation:
The repeating decimal equivalent would be 0.44, and round it to 0.49
Molecules of a toxic chemical eventually decompose into inert substances. Suppose the decomposition time is exponentially distributed with a mean of 1/lambda. The half-life of such a persistent poison is that time beyond which the probability is .50 that a particular molecule will remain toxic. Find the half-life for chemicals whose molecules have an average decomposition time of
Answer:
a)4.15 years
b)22.18 years
c)188.53 years
d)3027.66 years
Step-by-step explanation:
Formula : [tex]P(X\leq t)=1-e^{\frac{-t}{\lambda}}[/tex]
So, [tex]P(X>t)=1-(1-e^{\frac{-t}{\lambda}})[/tex]
[tex]P(X>t)=e^{\frac{-t}{\lambda}}[/tex]
We are given that The half-life of such a persistent poison is that time beyond which the probability is .50 that a particular molecule will remain toxic i.e. P(X>t)=0.5
So, [tex]e^{\frac{-t}{\lambda}}=0.5[/tex]
Taking natural log both sides
[tex]ln(e^{\frac{-t}{\lambda}})=ln(0.5)\\\frac{-t}{\lambda}=ln(0.5)\\t=-\lambda ln(0.5)[/tex]
a)
[tex]\lambda =6[/tex]
t=-(6) ln(0.5)=4.15 years
b)
[tex]\lambda =32[/tex]
t=-(32) ln(0.5)=22.18 years
c)
[tex]\lambda =272[/tex]
t=-(272) ln(0.5)=188.53 years
d)
[tex]\lambda =4368[/tex]
t=-(4368) ln(0.5)=3027.66 years
What is the value of the unknown in the equation 3m + 7 = - 23?
Answer:
Step-by-step explanation:
3m + 7 = - 23
we pass the -7 to the right with a positive sign
3m = -23 - 7
we perform the sum of negative numbers
3m = -30
we pass the -3 to the right to divide
m = -30/3
we perform the division
m = -10
Li counts 203 stars in the sky. The next night, she counts 178 stars. How many stars in all did she see on the two nights?
Answer:
203 + 178 = 381
Step-by-step explanation:
Answer:
381
Step-by-step explanation:
i added
203
+178
381
NB: NOT HOW I WANTED IT TO TURN OUT
SORRY IF IT'S WRONG
What is the value of 4x – 3y if x = 3 and y = 6?
Answer:
The value is -6.
Step-by-step explanation:
First, you use subsitution.
4(3) - 3(6)
Then, you multiply.
12 - 18
Do the subtraction and you're left with -6 as your answer.
given;, angle 2 = angle 4. angle 2 = 110
prove angle 3 = 70
Answer:
Step-by-step explanation:
180-110+70
I need lots of help
Answer:
with what
Step-by-step explanation:
Answer this for my sister again
Help my 11 old daughter please I don’t know this type of math
Answer:
2nd Choice- $2.14 total
Step-by-step explanation:
The expression is just adding the factors, 1.19 and 0.95. Then the counting sets, a whole square shaded is 100 units, a bit more is shaded of the second square, which signifies the .19 cents. Then yellow shade shows the lip balm cost, which is 0.95.
Mr. Smith and Ms. Jones start at the same place.
Mr. Smith drives north for 4 miles. Ms. Jones
drives east for 5 miles. What is the direct distance
between Mr. Smith and Ms. Jones?
A. 18 miles
B. 41 miles
C. 9 miles
D. 41 miles
Suppose that your boss must choose four employees in your office to attend a conference in Jamaica. Because all 12 of you want to go, he decides that the only fair way is to draw names out of a hat. What is the probability that you, Charles, Margaret, and Sean are chosen?
Using the combination formula, it is found that the probability that you, Charles, Margaret, and Sean are chosen is:
[tex]p = \frac{1}{495}[/tex].
What is the combination formula?[tex]C_{n,x}[/tex] is the number of different combinations of x objects from a set of n elements, given by:
[tex]C_{n,x} = \frac{n!}{x!(n-x)!}[/tex]
In this problem, 4 people will be chosen from a set of 12, hence the number of ways to choose them is:
[tex]C_{12,4} = \frac{12!}{4!8!} = 495[/tex]
The desired combination is only one, hence the probability is:
[tex]p = \frac{1}{495}[/tex].
More can be learned about the combination formula at https://brainly.com/question/25821700
#SPJ1
what is the product of 2(-4)
Answer:
-8
Step-by-step explanation:
First, write it out in standard form:
2 x (-4)
Then multiply!
Answer:
-8
Step-by-step explanation:
it is basically 2 x -4 and a negative times a positive is a negative which makes it -8
drag and drop each expression to correctly classify if it as having a positive or negative product just put them in order from positive to negative. WHOEVER GIVES ME THE RIGHT ANSWER I WILL MAKE BRAINLIEST
Answer:
The two in the middle are the negatives and the two that are on the sides are positive.
P(x)= - 4x + 2,800x - 400
A swester is 20 dollars and is on ssle for 12 dollars. What percentage off
12 dolars / 20 dolars
the percentage is
(20-12) / 20
= 8/20
= 40 %
least common multiple
3/6 , 2/12
Answer:
6
Step-by-step explanation:
3,6,9.12
2,4,6,8,10,12
Estimate by rounding the first factor to the nearest ten. Then enter the product.
77 × 5
The estimate is _______
The product is ________
Answer:
estimate - 400
product - 385
Step-by-step explanation:
estimate - 77 rounds up to 80
80*5=400
product - 70*5=350
7*5=35
350+35=385
Answer:
The estimate is 390 while the real product is 385
Need help ASAP have 30 minutes
Answer:
1 box of paper will cost $7.25.
Step-by-step explanation:
14.50 divided by 2 is 7.25, therefore one box of paper will be 7.25
Vijay is celebrating his birthday at Pizza Ranch. The all-you-can-eat meal costs $12 per adult
and $5 per child. He wants to stay under a budget of $180 for the party.
Select the inequality in standard form that describes this situation. Use the given numbers and the
following variables
• X = the number of adults attending
· y = the number of children attending
12x + 5y < 180
B
12x + 5y < 180
52 + 12y < 180
5x + 12y < 180
Answer:
12x+5y < 180
Step-by-step explanation:
12 (adults) + 5 (kids) < needs to be less than 180 dollars
Bags of flour at a local grocery store have a mean weight of 83 ounces with a standard deviation of 2 ounces. Which weight represents the 65th percentile?
A.82.2 ounces
B.82.5 ounces
C.83.5 ounces
D.83.8 ounces
Answer:
D.83.8 ounces
Step-by-step explanation:
The z score for 65th percentile = 0.385
Mean weight of 83 ounces with a standard deviation of 2 ounces
The formula for calculating a z-score is z = (x-μ)/σ
where x is the raw score
μ is the population mean
σ is the population standard deviation
x = ??
Hence:
0.385 = (x - 83)/2
Cross Multiply
0.385 × 2 = x - 83
0.77 = x - 83
x = 83 + 0.77
x = 83.77 ounces
Approximately = 83.8 ounces
Answer:
D.83.8 ounces
Step-by-step explanation:
The z score for 65th percentile = 0.385
Mean weight of 83 ounces with a standard deviation of 2 ounces
The formula for calculating a z-score is z = (x-μ)/σ
where x is the raw score
μ is the population mean
σ is the population standard deviation
x = ??
Hence:
0.385 = (x - 83)/2
Cross Multiply
0.385 × 2 = x - 83
0.77 = x - 83
x = 83 + 0.77
x = 83.77 ounces
Approximately = 83.8 ounces
Please help me if you know the correct answer, thank you
9515 1404 393
Answer:
Option 4Option 1no solutionStep-by-step explanation:
1. The system is represented by the matrix that has the coefficients in the left three columns and the constants in the rightmost column. Values and signs must match. Only Option 4 makes any sense in this context.
__
2. In the first equation, the y-term has a coefficient of 0. (There is no y-term.) The only matrix choice with a coefficient of 0 in the second column of the first row is Option 1.
__
3. Parallel lines do not intersect, so there can be no solution.
Find DF
Segment addition
Answer:
mDF = 18
Step-by-step explanation:
DE and EF must add up to DF.
Step 1: Set up equation
mDE + mEF = mDF
x + 7 + 7 = 4x + 2
Step 2: Solve for x
Combine like terms: x + 14 = 4x + 2Subtract x on both sides: 14 = 3x + 2Subtract 2 on both sides: 12 = 3xDivide both sides by 3: 4 = xRewrite: x = 4Step 3: Find mDF
mDF = 4x + 2
mDF = 4(4) + 2
mDF = 16 + 2
mDF = 18
Please help me. Will give brainliest.
Answer:
b.) (6,7)
Step-by-step explanation:
the figure is translated 2 units to the left
8 less than the product of 7 and -10.
The expression is
The value of the expression is 1
Answer:
um i dunna
Step-by-step explanation:
uuuuhhghhhh
Golfing
A golfer is aiming for a hole that is 120 feet away and, when he hits the golf ball off the ground, its highest point
reaches 80 feet up in the air
3
Step-by-step explanation:
Using vertex form of a parabola:
y = a (x − h)² + k
where (h, k) is the vertex.
If we say the vertex is (0, 80), then:
y = a (x − 0)² + 80
y = ax² + 80
The roots of the parabola are (-60, 0) and (60, 0). If we plug this in:
0 = a (60)² + 80
-80 = 3600a
a = -1/45
Noemi's team's answer is incorrect.
FIRST RIGHT GETS BRAINLIEST
Answer:
0?
Step-by-step explanation:
Which number is closest to V90 ?
7. A fish tank hold 100 gallons of water and is losing water at a rate of 1 gallons per hour. A second fish tank
contains 40 gallons of water is having 2 gallons added per hour. After how many hours will the first tank
have less water than the second? Which inequality represents the situation?
a. 100+ h > 40 - 2h
c. 40-h > 100 + 5h
b. 100-h< 40 + 2h
d. 100-h > 40 + 2h
OA
OB
ОС
D
D
Question 8
My
Answer:
B
Step-by-step explanation:
the first fish tank has 100 gallons of water and 1 gallon is removed every hour which makes 100-h
the second tank has 40 gallons in it and 2 gallons are added every hour which makes 40+2h
after 20 hours the second tank will have more gallons than the first tank
this means that 40+2h would be greater than 100-h since it's also asking you "After how many hours will the first tank have less water than the second?"
Jackson can lay 6000ft of tile in 3 hours.
What is Jackson's rate?
A.200ft/h
B.1500ft/h
C.2000
D.18000f/h
Answer:
It's 2000ft/h
Step-by-step explanation:
6000/3 = 1 hour rate
Will mark Brainliest, 15 points. Easy question.
The point slope form of the line that passes through
(-4, -3) and (12, 1) is
y - 1 = 1/4 ( x - 12). What is the standard form of the equation for this line?
A). X - 4y = 8
B). X - 4y = 2
C). 4x - y = 8
D). 4x - y = 2
answers please.......
Answer:
$69.375
Step-by-step explanation:
To find the total cost: you will add the actual cost of the rug, $64 and the additional shipping and handling cost, $5.375.
[tex]64 + 5.375 = 69.375[/tex]
The total cost of the rug, including shipping and handling is $69.375
Answer:
$69.38
Step-by-step explanation:
64 plus 5 is 69. Add 375 for 69.375. Round the decimal up to get $69.38