Answer:
x = 128.472
Step-by-step explanation:
To solve this question, we need to understand the normal probability distribution and the central limit theorem.
Normal Probability Distribution
Problems of normal distributions can be solved using the z-score formula.
In a set with mean [tex]\mu[/tex] and standard deviation [tex]\sigma[/tex], the z-score of a measure X is given by:
[tex]Z = \frac{X - \mu}{\sigma}[/tex]
The Z-score measures how many standard deviations the measure is from the mean. After finding the Z-score, we look at the z-score table and find the p-value associated with this z-score. This p-value is the probability that the value of the measure is smaller than X, that is, the percentile of X. Subtracting 1 by the p-value, we get the probability that the value of the measure is greater than X.
Central Limit Theorem
The Central Limit Theorem establishes that, for a normally distributed random variable X, with mean [tex]\mu[/tex] and standard deviation [tex]\sigma[/tex], the sampling distribution of the sample means with size n can be approximated to a normal distribution with mean [tex]\mu[/tex] and standard deviation [tex]s = \frac{\sigma}{\sqrt{n}}[/tex].
For a skewed variable, the Central Limit Theorem can also be applied, as long as n is at least 30.
The number of diners each day has a mean of 107 and a standard deviation of 60.
This means that [tex]\mu = 107, \sigma = 60[/tex]
Distribution of the daily average:
Over a month of 30 days, so [tex]n = 30, s = \frac{60}{\sqrt{30}} = 10.955[/tex]
The probability that a daily average over a given month is greater than x is 2.5%. Calculate x.
This is X when Z has a p-value of 1 - 0.025 = 0.975, so X when Z = 1.96. Then
[tex]Z = \frac{X - \mu}{\sigma}[/tex]
By the Central Limit Theorem
[tex]Z = \frac{X - \mu}{s}[/tex]
[tex]1.96 = \frac{X - 107}{10.955}[/tex]
[tex]X - 107 = 1.96*10.955[/tex]
[tex]X = 128.472[/tex]
So x = 128.472
How long will it take 500 dollars to double if it is invested at 7% interest compounded semi-annually
Answer:
11 half years
Step-by-step explanation:
The formula for compound interest is
A = P(1+r/n)^(nt), with r representing the interest rate, n being the number of times interest is applied over the time period, and t being the amount of time periods.
If we make the time period a half year (so interest is compounded once per time period), n=2. Then, our interest rate is 7%, or 0.07 (to convert from percent to decimal, simply divide by 100). Our starting amount is 500, and we want it to double, making it 1000. Our formula is thus
1000 = 500 (1+0.07)^(t)
divide both sides by 500
2 = (1+0.07)^(t)
2 = (1.07)^(t)
Using logarithms, we can say that
[tex]log_{1.07} 2 = t[/tex]
and using a calculator, we get
10.24 = t
Since interest is only compounded once per time period, though, we have to round up to make sure it doubles, so t = 11
Can someone help me with this? Thanks!
9514 1404 393
Answer:
x ∈ {5, 7}(5,7)Step-by-step explanation:
The graph shows the function value is zero for x=5 and x=7. These are the elements of the solution set.
x ∈ {5, 7}
__
The graph is below the x-axis between these points, so that is the region where f(x) < 0
5 < x < 7 . . . . . for f(x) < 0
In interval notation: (5, 7).
If 3 3/4m of cloth was used for one suit, how many suits can be made with 30m cloth
Answer:
8 suits
Step-by-step explanation:
Divide 30 m by 3 [tex]\frac{3}{4}[/tex] m , or 30 ÷ 3.75 , then
30 ÷ 3.75 = 8
Then 8 suits can be made from 30 m of cloth
Math help please ………….
Answer:
if the terms are approaching zero then it is convergent.
Therefore the stated series is convergent
Step-by-step explanation:
The life of light bulbs is distributed normally. The standard deviation of the lifetime is 15 hours and the mean lifetime of a bulb is 520 hours. Find the probability of a bulb lasting for at most 528 hours. Round your answer to four decimal places.
Answer:
0.7031 = 70.31% probability of a bulb lasting for at most 528 hours.
Step-by-step explanation:
Normal Probability Distribution
Problems of normal distributions can be solved using the z-score formula.
In a set with mean [tex]\mu[/tex] and standard deviation [tex]\sigma[/tex], the z-score of a measure X is given by:
[tex]Z = \frac{X - \mu}{\sigma}[/tex]
The Z-score measures how many standard deviations the measure is from the mean. After finding the Z-score, we look at the z-score table and find the p-value associated with this z-score. This p-value is the probability that the value of the measure is smaller than X, that is, the percentile of X. Subtracting 1 by the p-value, we get the probability that the value of the measure is greater than X.
The standard deviation of the lifetime is 15 hours and the mean lifetime of a bulb is 520 hours.
This means that [tex]\sigma = 15, \mu = 520[/tex]
Find the probability of a bulb lasting for at most 528 hours.
This is the p-value of Z when X = 528. So
[tex]Z = \frac{X - \mu}{\sigma}[/tex]
[tex]Z = \frac{528 - 520}{15}[/tex]
[tex]Z = 0.533[/tex]
[tex]Z = 0.533[/tex] has a p-value of 0.7031
0.7031 = 70.31% probability of a bulb lasting for at most 528 hours.
Seth and Ted can paint a room in 5 hours if they work together. If Ted were to work by himself, it would take him 2 hours longer than it would take Seth working by himself. How long would it take Seth to paint the room by himself if Ted calls in sick?
Answer:
9 hours
Step-by-step explanation:
Let
x = number of hours it would take Seth to work by himself
He would paint 1/x in 1 hour
x + 2 = number of hours it would take Ted to work by himself
He would paint 1/(x + 2) in 1 hour
Seth and Ted = 5 hours
They would paint 1/5 in 1 hour
The equation is this:
1/x + 1/(x + 2) = 1/5
(x + 2)+x/x(x+2) = 1/5
x+2+x / x(x+2) = 1/5
2x + 2 / x(x+2) = 1/5
2x + 2 = x(x + 2)1/5
2x + 2 = (x² + 2x)1/5
5(2x + 2) = x² + 2x
10x + 10 = x² + 2x
x² + 2x - 10x - 10 = 0
x² - 8x - 10 = 0
x = -b ± √b² - 4ac/2a
= -(-8) ± √(-8)² - 4(1)(-10) / 2(1)
= 8 ± √64 - (-40) / 2
= 8 ± √64 + 40) / 2
= 8 ± √104 / 2
= 8 ± 2√26 / 2
= 8/2 ± 2√26/2
= 4 ± √26
= 4 ± 5.0990195135927
= 4 + 5.0990195135927 or 4 - 5.0990195135927
= 9.0990195135927 or -1.Answer:
Step-by-step explanation:
Let
x = number of hours it would take Seth to work by himself
He would paint 1/x in 1 hour
x + 2 = number of hours it would take Ted to work by himself
He would paint 1/(x + 2) in 1 hour
Seth and Ted = 5 hours
They would paint 1/5 in 1 hour
The equation is this:
1/x + 1/(x + 2) = 1/5
(x + 2)+x / x(x+2) = 1/5
x+2+x / x(x+2) = 1/5
2x + 2 / x(x+2) = 1/5
Cross product
2x + 2 = x(x + 2)1/5
2x + 2 = (x² + 2x)1/5
Cross product
5(2x + 2) = x² + 2x
10x + 10 = x² + 2x
x² + 2x - 10x - 10 = 0
x² - 8x - 10 = 0
x = -b ± √b² - 4ac/2a
= -(-8) ± √(-8)² - 4(1)(-10) / 2(1)
= 8 ± √64 - (-40) / 2
= 8 ± √64 + 40) / 2
= 8 ± √104 / 2
= 8 ± 2√26 / 2
= 8/2 ± 2√26/2
= 4 ± √26
= 4 ± 5.0990195135927
= 4 + 5.0990195135927 or 4 - 5.0990195135927
= 9.0990195135927 or -1.0990195135927
Approximately,
x = 9 hours or -1 hour
It can't take Seth negative hours to work
Therefore,
x = number of hours it would take Seth to work by himself = 9 hours
State sales tax y is directly proportional to retail price x. An item that sells for 156 dollars has a sales tax of 14.42 dollars. Find a mathematical model that gives the amount of sales tax y in terms of the retail price x .
What is the sales tax on a 320 dollars purchase.
Answer:
The sales tax on a 320 dollars purchase is of $29.6.
Step-by-step explanation:
State sales tax y is directly proportional to retail price x.
This means that:
[tex]y = cx[/tex]
In which c is the constant of proportionality.
An item that sells for 156 dollars has a sales tax of 14.42 dollars.
This means that [tex]x = 156, y = 14.42[/tex]. We use this to find c. So
[tex]y = cx[/tex]
[tex]14.42 = 156c[/tex]
[tex]c = \frac{14.42}{156}[/tex]
[tex]c = 0.0924[/tex]
Then
[tex]y = 0.0924x[/tex]
What is the sales tax on a 320 dollars purchase?
y when [tex]x = 320[/tex]. So
[tex]y = 0.0924(320) = 29.6[/tex]
The sales tax on a 320 dollars purchase is of $29.6.
Solve y = -7(-13)
I'm giving 30 points!
y = -7(-13)
=> y = -7 × (-13)
= y = 91
I will assign a question at around 9:00 today (July 3, 2021) for a huge amount of points. I won’t say where on Brainly. Good luck.
Answer:
ಠ_ಠ
Step-by-step explanation:
which statements are true for the functions g(x)=x^2 and h(x)=-x^2? Check all that apply
Answer:
if x=0 then they have same value
1 and 2 options are out
for x=-1
g(-1)=1
h(-1)=-1
3 is true
4th
FALSE
for all values except 0, g(x)>h(x)
correct ones are
g(x) > h(x) for x = -1.
For positive values of x, g(x) > h(x).
For negative values of x, g(x) > h(x).
Step-by-step explanation:
For each of the following variables, identify the type of variable (categorical vs. numeric). (1) Temperature (in Fahrenheit) of an office building (11) Traffic congestion (e.g. light, medium, heavy)
1) (1) Numeric, and (II) Categorical
2) (1) Numeric, and (II) Numeric
3) (1) Categorical, and (II) Numeric
4) There is no correct match.
5) (1) Categorical, and (11) Categorical
Answer:
(a) Temperature: Numerical
(b) Traffic congestion: Categorical
Step-by-step explanation:
Required
Determine the variable type
(a) Temperature
Temperatures are measured in numeric values e.g. 22 degree Fahrenheit, etc.
Hence, the variable is numerical
(b) Traffic congestion
From the question, we understand that the traffic congestion are divided into three categories i.e. light, medium....
Hence, the variable is categorical
Deon bought a desk on sale for $105.60. This price is 67% less than the original price. What was the original price?
Answer:
.33x = 105.60
$371
Step-by-step explanation:
Answer:
63.44
Step-by-step explanation:
its 63.44697 but you round so its 63.44
What is the volume of the composite figure if both the height and the diameter of the cylinder are 3.5 feet? Give the exact answer and approximate to two decimal places.
Answer:
Volume of composite figure = 44.9 feet³
Step-by-step explanation:
Given:
Height of cylinder = 3.5 feet
Diameter of cylinder = 3.5 feet
Diameter of hemisphere = 3.5 feet
Find:
Volume of composite figure
Computation:
Radius of cylinder and sphere = 3.5/2 = 1.75 feet
Volume of composite figure = Volume of cylinder + Volume of hemisphere
Volume of composite figure = πr²h + (2/3)πr³
Volume of composite figure = (3.14)(1.75)²(3.5) + (2/3)(3.14)(1.75)³
Volume of composite figure = (3.14)(3.0625)(3.5) + (2/3)(3.14)(5.359375)
Volume of composite figure = 33.656875 + 11.2189583
Volume of composite figure = 44.8758
Volume of composite figure = 44.9 feet³
The function ()=5^3+3x−6 has inverse function . Find ′(138).
9514 1404 393
Answer:
f⁻¹(138) = 3
Step-by-step explanation:
You want to find the value of x that makes the function have a value of 138:
f(x) = 5x^3 +3x -6
138 = 5x^3 +3x -6
0 = 5x^3 +3x -144
Descartes's rule of signs tells us this has one positive real solution. The rational root theorem gives us 30 possibilities. Rewriting the equation as ...
x^3 = (144 -3x)/5 = 28.8 -0.6x
suggests that the value of x is less than ∛28.8 ≈ 3.065. Trying x=3, we find that to be a solution.
(5x² +3)(x) -6 = 0 . . . . rewrite of the above equation
(5·3² +3)·3 -144 = (48)(3) -144 = 0 . . . . true
Then ...
f⁻¹(138) = 3
_____
The answer is found easily using a graphing calculator. The solution is the x-intercept of 138 -f(x) = 0.
Describe how the graph of y = |x - 2| - 5 is a transformation of the graph of y = |x|. Use terms such as "shifted", "reflected", "stretched", or "compressed".
Answer:
The original graph was shifted 2 units to the left and 5 units down.
Step-by-step explanation:
y = |x|
From this, we go to: y = |x - 2|.
When we want to shift a function f(x) a units to the left, we find f(x - a). So first, the graph was shifted 2 units to the left.
y = |x - 2|.
From this, we go to: y = |x - 2| - 5.
Shifting a function f(x) down b units is the same as finding f(x) - b, so the second transformation was shifting the graph 5 units down.
The triangles are similar by??
the SAS similarity theorem
it is estimated that 50% of emails are spam emails. Some software has been applied to filter these spam emails before they reach your inbox. A certain brand of software claims that it can detect 99% of spam emails and the probability for a flase positive is 5%. What is the probability that an email is detected as spam
Answer:
0.52 = 52% probability that an email is detected as spam.
Step-by-step explanation:
Probability that an email is detected as spam:
99% of 50%(are spam).
5% of 100 - 50 = 50%(false positives, that is, e-mails that are not spam but are detected as spams).
What is the probability that an email is detected as spam?
[tex]p = 0.99*0.5 + 0.05*0.5 = 0.52[/tex]
0.52 = 52% probability that an email is detected as spam.
238.64 yards.what is the diameter of the field?use 3.14 for pie and do not round your answer
Answer:
It should be 8.6 yards, as 238.64÷3.14 = 74.
√74 = 8.60, or 8.6 :)
Hello, please help me!!
Answer:
0.14
Step-by-step explanation:
P(A|B) asks for the probability of A, given that B has happened. This is equal to the probability of A and B over the probability of B (see picture)
Here, the question is asking if someone is taking the bus given that they are a senior.
The probability of someone being a senior and taking the bus is 5/100, or 0.05 . The probability of someone being a senior is 35/100, or 0.35
Our answer is then 0.05/0.35 = 1/7 = 0.14
Exercise 2.2.3: The cardinality of a power set. (a) What is the cardinality of P({1, 2, 3, 4, 5, 6})
Answer:
Cardinality of the power set of the given set = [tex]2^6=64[/tex]
Step-by-step explanation:
Power set is the set of all the possible subsets that can be formed from the given set including the null set and the set itself.
Example set:
{1,2,3}
All the possible subsets of this set:
{}; {1}; {2}; {3}; {1,2,3}; {1,2}; {1,3}; {2,3}
The power set of the above set is written as:
P({ {}, {1}, {2}, {3}, {1,2}, {1,3}, {2,3}, {1,2,3} })
Since the no. of elements in the above power set in this example is 8 therefore its cardinality is 8.
Cardinality of the power set of a given set is expressed by a formula: [tex]2^n[/tex]
where n is the cardinality (no. of elements) of the given set whose power set is to be formed for determining cardinality of the power set.
Hence in the given case, we have n = 6.
what is the LCM of 2 Express on if there is no common factor
Answer:
I started by dividing 2940 by the smallest prime that would fit into it, being 2. This left me with another even number, 1470, so I divided by 2 again. The result, 735, is divisible by 5, but 3 divides in also, and it's smaller, so I divided by 3 to get 245. This is not divisible by 3 but is divisible by 5, so I divided by 5 and got 49, which is divisible by 7.
Suppose Z has a normal distribution with a mean of 10.0 and a standard deviation of 5.0 what is the P(2.0
Answer:
.0548
Step-by-step explanation:
(2-10)/5= -1.6
go to a ztable and get .0548
Suppose the sales (1000s of $) of a fast food restaurant are a linear function of the number of competing outlets within a 5 mile radius and the population (1000s of people) within a 1 mile radius. The regression equation quantifying this relation is (sales)
Answer:
[tex]Sales = 86.749[/tex]
Step-by-step explanation:
Given
[tex]Sales = 0.845*(competitors) + 5.79*(population) + 13.889[/tex]
[tex]Competitors = 4[/tex]
[tex]Population = 12000[/tex]
See comment for complete question
Required
The sales
We have:
[tex]Sales = 0.845*(competitors) + 5.79*(population) + 13.889[/tex]
Substitute values for competitors and population
[tex]Sales = 0.845*4 + 5.79*12 + 13.889[/tex]
[tex]Sales = 3.38 + 69.48 + 13.889[/tex]
[tex]Sales = 86.749[/tex]
A strawberry farmer in Poteet knows that 1/8 of his strawberries are typically not fit to sell at the market (either because they went bad or are too unusually shaped). The farmer takes a random sample of 156 strawberries to inspect for the upcoming farmer's market and finds that 24 are unfit to sell. If he were to go back and pick 1000 more strawberries to inspect for the market, how would the standard deviation of the sample proportion be affected
Answer:
It would be smaller.
Step-by-step explanation:
Given that :
The number of the strawberries that are unfit for sell, x = 24
The total number of the strawberries to inspect, n = 156
Total number of the strawberries to be picked = 1000 strawberries
Therefore,
[tex]$\widehat p =\frac{x}{n}$[/tex]
[tex]$=\frac{24}{156}$[/tex]
= 0.1538
[tex]$\widehat p =\frac{x}{n}$[/tex]
[tex]$=\frac{24}{1000}$[/tex]
= 0.024
Therefore, the standard deviation of the sample proportion would be smaller.
If interest is 8% and it is compounded semiannually, and after one year, the total value is $10,816, what was the original investment?
Find the value of x in the kite below.
60°
O
x = [?]
Answer:
30
Step-by-step explanation:
The given is right triangle with angle measure 90-60 and 30 degrees as we can see on the image.
lenguaje coloquial de x-y
Answer:
Uhh what??
Step-by-step explanation:
I dont understand you ●___●
change the following basis to Base 10 134 in base seven
Answer:
74 base 10.
Step-by-step explanation:
134 base 7 = 7^2 + 3*7 + 4
= 49 + 21 + 4
= 74 base 10
(x+2)(x+3)(x+4)(x+5)-48
Can the range of a function be written like this {6,7,8,10} instead of like this [tex]6\leq x\leq 10[/tex]?
Answer:
No unless x is being used to define only elements of an integer set.
Step-by-step explanation:
No, not in general unless x is defined as a integer or a subset of the integers like the naturals, whole numbers....
Usually 6<=x<=10 means all real numbers between 6 and 10, inclusive. This means example that 6.6 or 2pi are in this set with infinitely other numbers that I can't name.
{6,7,8,9,10} just means the set containing the numbers 6,7,8,9,10 and that's only those 5 numbers.
