Answer:
(A) The probability that a male spent less than $210 online before deciding to visit a store is 0.0668.
(B) The probability that a male spent between $270 and $300 online before deciding to visit a store is 0.0655.
(C) Ninety percent of the amounts spent online by a male before deciding to visit a store is less than $265.632.
Step-by-step explanation:
We are given that the reports indicate that men spend an average of $240 online before they decide to visit a store. If the spending limit is normally distributed and the standard deviation is $20.
Let X = the spending limit
The z-score probability distribution for the normal distribution is given by;
Z = [tex]\frac{X-\mu}{\sigma}[/tex] ~ N(0,1)
where, [tex]\mu[/tex] = mean spending limit = $240
[tex]\sigma[/tex] = standard deviation = $20
So, X ~ Normal([tex]\mu=\$240,\sigma^{2} =\$20^{2}[/tex])
(A) The probability that a male spent less than $210 online before deciding to visit a store is given by = P(X < $210)
P(X < $210) = P( [tex]\frac{X-\mu}{\sigma}[/tex] < [tex]\frac{\$210-\$240}{\$20}[/tex] ) = P(Z < -1.50) = 1 - P(Z [tex]\leq[/tex] 1.50)
= 1 - 0.9332 = 0.0668
The above probability is calculated by looking at the value of x = 1.50 in the z table which has an area of 0.9332.
(B) The probability that a male spent between $270 and $300 online before deciding to visit a store is given by = P($270 < X < $300)
P($270 < X < $300) = P(X < $300) - P(X [tex]\leq[/tex] $270)
P(X < $300) = P( [tex]\frac{X-\mu}{\sigma}[/tex] < [tex]\frac{\$300-\$240}{\$20}[/tex] ) = P(Z < 3) = 0.9987
P(X [tex]\leq[/tex] $270) = P( [tex]\frac{X-\mu}{\sigma}[/tex] [tex]\leq[/tex] [tex]\frac{\$270-\$240}{\$20}[/tex] ) = P(Z [tex]\leq[/tex] 1.50) = 0.9332
The above probability is calculated by looking at the value of x = 3 and x = 1.50 in the z table which has an area of 0.9987 and 0.9332 respectively.
Therefore, P($270 < X < $300) = 0.9987 - 0.9332 = 0.0655.
(C) Now, we have to find ninety percent of the amounts spent online by a male before deciding to visit a store is less than what value, that is;
P(X < x) = 0.90 {where x is the required value}
P( [tex]\frac{X-\mu}{\sigma}[/tex] < [tex]\frac{x-\$240}{\$20}[/tex] ) = 0.90
P(Z < [tex]\frac{x-\$240}{\$20}[/tex] ) = 0.90
In the z table, the critical value of z that represents the bottom 90% of the area is given as 1.2816, i.e;
[tex]\frac{x-\$240}{\$20}=1.2816[/tex]
[tex]x-240=1.2816\times 20[/tex]
[tex]x=240 + 25.632[/tex]
x = 265.632
Hence, Ninety percent of the amounts spent online by a male before deciding to visit a store is less than $265.632.
Let x represent the number of times a student visits a gym in a one month period. Assume that the probability distribution of X is as follows:
x 0 1 2 3
p(x) 0.37 0.29 0.22 0.12
Find the mean, of this distribution. Report your answer to two decimal places.
Answer:
1.86
Step-by-step explanation:
Given the following :
X : - - - - 0 - - - - 1 - - - - 2 - - - - - 3 - - - - 4
P(x) - 0.37 - - 0.28 - - 0.22 - - 0.22 - - 0.12
The mean of the distribution can be calculated by evaluated by determining the expected value of the distribution given that the data above is a discrete random variable. The mean value can be deduced multiplying each possible outcome by the probability of it's occurrence.
Summation of [P(x) * X] :
(0.37 * 0) + (0.28 * 1) + (0.22 * 2) + (0.22 * 3) + (0.12 * 4)
= 0 + 0.28 + 0.44 + 0.66 + 0.48
= 1.86
Kelly bought a cup of coffee and drank 58 of it. Write an addition equation to represent how much coffee is remaining.
Answer:
[tex]L + \frac{5}{8} = 1[/tex]
Step-by-step explanation:
Given
A cup of coffee
Kelly drank 5/8 of the coffee
Required
Determine how much is left
Start by representing the amount of coffee left with L
Because the amount of coffee Kelly drank is in fraction (5/8), the total cup of coffee will equate to 1;
Hence, the addition equation as requested in the question to represent the scenario is
[tex]L + \frac{5}{8} = 1[/tex]
janice is buying paint to paint her new apartment
Answer:
I canot answer this
Step-by-step explanation:
Find the work done by the force field F(x,y,z)=6xi+6yj+6k on a particle that moves along the helix r(t)=3 cos(t)i+3sin(t)j+2 tk,0≤t≤2π.
Answer:
the work done by the force field = 24 π
Step-by-step explanation:
From the information given:
r(t) = 3 cos (t)i + 3 sin (t) j + 2 tk
= xi + yj + zk
∴
x = 3 cos (t)
y = 3 sin (t)
z = 2t
dr = (-3 sin (t)i + 3 cos (t) j + 2 k ) dt
Also F(x,y,z) = 6xi + 6yj + 6k
∴ F(t) = 18 cos (t) i + 18 sin (t) j +6 k
Workdone = 0 to 2π ∫ F(t) dr
[tex]\mathbf{= \int \limits ^{2 \pi} _{0} (18 cos (t) i + 18 sin (t) j +6k)(-3 sin (t)i+3cos (t) j +2k)\ dt}[/tex]
[tex]\mathbf{= \int \limits ^{2 \pi} _{0} (-54 \ cos (t).sin(t) + 54 \ sin (t).cos (t) + 12 ) \ dt}[/tex]
[tex]\mathbf{= \int \limits ^{2 \pi} _{0} 12 \ dt}[/tex]
[tex]\mathbf{= 12 \times 2 \pi}[/tex]
= 24 π
A researcher wishes to determine whether people with high blood pressure can lower their blood pressure by performing yoga exercises. A treatment group and a control group are selected. The sample statistics are given below. Construct a 90% confidence interval for the difference between the two population means, Would you recommend using yoga exercises? Treatment Group Control Group n1 = 100 n2 = 100 1 = 178 2 = 193 s1 = 35 s2 = 37
Answer:
90% confidence interval for the difference between the two population means
( -23.4166 , -6.5834)
Step-by-step explanation:
Step(i):-
Given first sample size n₁ = 100
Given mean of the first sample x₁⁻ = 178
Standard deviation of the sample S₁ = 35
Given second sample size n₂= 100
Given mean of the second sample x₂⁻ = 193
Standard deviation of the sample S₂ = 37
Step(ii):-
Standard error of two population means
[tex]se(x^{-} _{1} -x^{-} _{2} ) = \sqrt{\frac{s^{2} _{1} }{n_{1} }+\frac{s^{2} _{2} }{n_{2} } }[/tex]
[tex]se(x^{-} _{1} -x^{-} _{2} ) = \sqrt{\frac{(35)^{2} }{100 }+\frac{(37)^{2} }{100 } }[/tex]
[tex]se(x^{-} _{1} -x^{-} _{2} ) = 5.093[/tex]
Degrees of freedom
ν = n₁ +n₂ -2 = 100 +100 -2 = 198
t₀.₁₀ = 1.6526
Step(iii):-
90% confidence interval for the difference between the two population means
[tex](x^{-} _{1} - x^{-} _{2} - t_{\frac{\alpha }{2} } Se (x^{-} _{1} - x^{-} _{2}) , x^{-} _{1} - x^{-} _{2} + t_{\frac{\alpha }{2} } Se (x^{-} _{1} - x^{-} _{2})[/tex]
(178-193 - 1.6526 (5.093) , 178-193 + 1.6526 (5.093)
(-15-8.4166 , -15 + 8.4166)
( -23.4166 , -6.5834)
(a) Find the standard error of the mean for each sampling situation (assuming a normal population). (Round your answers to 2 decimal places.) (a) σ = 18, n = 9 (b) σ = 18, n = 36 (c) σ = 18, n = 144
Answer:
a) 6.00
b) 3.00
c) 1.50
Step-by-step explanation:
Sample error of the mean is expressed mathematically using the formula;
SE = σ /√n where;
σ is the standard deviation and n is the sample size.
a) Given σ = 18, n = 9
Standard error of the mean = σ /√n
Standard error of the mean = 18/√9
Standard error of the mean = 18/3
Standard error of the mean = 6.00
b) Given σ = 18, n = 36
Standard error of the mean = σ /√n
Standard error of the mean = 18/√36
Standard error of the mean = 18/6
Standard error of the mean = 3.00
c) Given σ = 18, n = 144
Standard error of the mean = σ /√n
Standard error of the mean = 18/√144
Standard error of the mean = 18/12
Standard error of the mean = 3/2
Standard error of the mean = 1.50
Find the minimum sample size needed to estimate the percentage of Democrats who have a sibling. Use a 0.1 margin of error, use a confidence level of 98%, and use the results from a prior Harris poll that gave a confidence interval of (0.44, 0.51) for the proportion of Democrats who have a sibling.
Answer:
The minimum sample size is [tex]n =135[/tex]
Step-by-step explanation:
From the question we are told that
The confidence interval is [tex]( lower \ limit = \ 0.44,\ \ \ upper \ limit = \ 0.51)[/tex]
The margin of error is [tex]E = 0.1[/tex]
Generally the sample proportion can be mathematically evaluated as
[tex]\r p = \frac{ upper \ limit + lower \ limit }{2}[/tex]
[tex]\r p = \frac{ 0.51 + 0.44}{2}[/tex]
[tex]\r p = 0.475[/tex]
Given that the confidence level is 98% then the level of significance can be mathematically evaluated as
[tex]\alpha = 100 - 98[/tex]
[tex]\alpha = 2\%[/tex]
[tex]\alpha =0.02[/tex]
Next we obtain the critical value of [tex]\frac{\alpha }{2}[/tex] from the normal distribution table
The value is
[tex]Z_{\frac{\alpha }{2} } = 2.33[/tex]
Generally the minimum sample size is evaluated as
[tex]n =[ \frac { Z_{\frac{\alpha }{2} }}{E} ]^2 * \r p (1- \r p )[/tex]
[tex]n =[ \frac { 2.33}{0.1} ]^2 * 0.475(1- 0.475 )[/tex]
[tex]n =135[/tex]
60 is x% of 12. Find the value of x.
Answer:
20
Step-by-step explanation:
We can set up a percentage proportion to find the value of x.
[tex]\frac{12}{x} = \frac{60}{100}[/tex]
Now we cross multiply:
[tex]100\cdot12=1200\\\\1200\div60=20[/tex]
Hope this helped!
15 < −5x can someone please solve for x?
Answer:
x <-3
Step-by-step explanation:
15 <-5x
divide both sides by 5 but since the coefficient of x is negative after dividing the sign changes.
x <-3
Answer:
x < −3
I hope this helps!
PLEASE HELP!!! Determine the domain and range of the following function. Record your answers in set notation.
Answer:
Ok so to help you out, first, off you need to be sure that the sets domain and range use the proper variable. After that, you are going to want to just plug it into the equation. I am going to link a screenshot to the correct answer if you are still have trouble finding it.
Anyways hoped this helped and I got to this question in time c:
A mail truck traveled 82 miles in 4 1/2 hours. The distance is the product of the rate and the time. To the nearest tenth, what was the average speed of the mail truck?
Answer:
= 18.2 miles per hour
Step-by-step explanation:
Speed = distance / time
=82 miles / 4.5 hours
=18.22222222 miles per hour
Rounding
= 18.2 miles per hour
Answer:
Given that
Distance = rate × time
82 = r × 4½
r = 18.2 mph
A baseball player has a batting average (probability of getting on base per time at bat) of 0.215. Based on this: What is the probability that they will get on base more than 6 of the next 15 at bats
Answer:
[tex]\mathbf{P(x>6) = 0.0265}[/tex]
Step-by-step explanation:
Given that:
A baseball player has a batting average (probability of getting on base per time at bat) of 0.215
i.e
let x to be the random variable,
consider [tex]x_1 = \left \{ {{1} \atop {0}} \right.[/tex] to be if the baseball player has a batting average or otherwise.
Then
p(x₁ = 1) = 0.125
What is the probability that they will get on base more than 6 of the next 15 at bats
So
[tex]\mathtt{x_i \sim Binomial (n,p)}[/tex]
where; n = 15 and p = 0.125
P(x>6) = P(x ≥ 7)
[tex]P(x>6) = \sum \limits ^{15}_{x=7} ( ^{15 }_x ) \ (0.215)^x \ (1 - 0.215)^{15-x}[/tex]
[tex]P(x>6) = 1 - \sum \limits ^{6}_{x=7} ( ^{15 }_x ) \ (0.215)^x \ (1 - 0.215)^{15-x}[/tex]
[tex]P(x>6) = 1 - \sum \limits ^{6}_{x=0} ( ^{15 }_x ) \ (0.215)^x \ (1 - 0.215)^{15-x}[/tex]
[tex]P(x>6) = 1 -0.9735[/tex]
[tex]\mathbf{P(x>6) = 0.0265}[/tex]
area please it's easy plzzzzzzzzzz
a ) Now as you can see, the white region is composed of a triangle and a rectangle. This triangle has a height of 5, as it is composed of the respective blank triangles. It's base is 5 meters as well, by properties of a rectangle - which is sufficient information to solve for the area of the triangle.
Area of Triangle : 1 / 2 [tex]*[/tex] 4 [tex]*[/tex] 5 = 2 [tex]*[/tex] 5 = 10 m²
The area of this rectangle will be 3 [tex]*[/tex] 4 = 12 m², considering it's given dimensions are 3 by 4. Therefore the area of this white region will be 10 + 12 = 22 m²
b ) Now this striped region will be the remaining area, or the area of the white region subtracted from the area of the outer rectangle.
Area of Outer Rectangle : 10 [tex]*[/tex] 4 = 40 m²,
Area of Striped Region : 40 - 22 = 18 m²
in the diagram EF and GH are straight lines. Find the values of a,b,c and d
find the circle through (-4,sqrt(5) with center (0,0)
Answer:
Circle Equation : x² + y² = 21
Step-by-step explanation:
So we know that this circle goes through the point ( - 4, √5 ), with a center being the origin. Therefore, this makes the circle equation a bit simpler.
The first step in determining the circle equation is the length of the radius. Applying the distance formula, the radius would be the length between the given points. Another approach would be creating a right triangle such that the radius is the hypotenuse. Knowing the length of the legs as √5 and 4, we can calculate the radius,
( √5 )² + ( 4 )² = r²,
5 + 16 = r²,
r = √21
In general, a circle equation is represented by the formula ( x - a )² + ( y - b )² = r², with radius r centered at point ( a, b ). Therefore our circle equation will be represented by the following -
( x - 0 )² + ( y - 0 )² = (√21 )²
Circle Equation : x² + y² = 21
Please help me so confused
Answer:
m = 15
Step-by-step explanation:
m/9 + 2/3 = 7/3
Subtract 2/3 from each side
m/9 + 2/3 -2/3= 7/3 -2/3
m/9 = 5/3
Multiply each side by 9
m/9 *9 = 5/3 *9
m = 15
GCF/LCM of 8 and 24 the reduce 8/24
Answer:
GCF(8, 24) = 8LCM(8, 24) = 248/24 = 1/3Step-by-step explanation:
Since 8 is a factor of 24, 8 is the GCF of the pair, and 24 is the LCM of the pair.
__
The ratio 8/24 is reduced by observing that 24 = 8·3:
8/24 = 8/(8·3) = (8/8)·(1/3)
8/24 = 1/3
what is ap in math abreviation and explain my math teacher was drunk so he couldn't teach nothing
Step-by-step explanation:
n mathematics, an arithmetic progression (AP) or arithmetic sequence is a sequence of numbers such that the difference between the consecutive terms is constant. ... For instance, the sequence 5, 7, 9, 11, 13, 15, . . . is an arithmetic progression with common difference of 2.
Why is a rhombus considered a type of quadrilateral?
Answer:
Well a rhombus is considered a quadrilateral because it has 4 sides and 4 angles.
Just like a square and rectangle they both are quadrilaterals with 4 angles and sides.
A rhombus is considered a type of quadrilateral because it has four sides and four angles
How to determine the reason?As a general rule, a shape that is considered a quadrilateral must have:
4 sides4 anglesSince a rhombus has four sides and four angles, then it is considered a type of quadrilateral
Read more about rhombus at:https://brainly.com/question/20627264
#SPJ6
Why would a linear function be an appropriate model?
Answer:
I know the answer
Step-by-step explanation:
Linear functions are those whose graph is a straight line. A linear function has the following form. y = f(x) = a + bx. A linear function has one independent variable and one dependent variable. The independent variable is x and the dependent variable is y.
The length of the sides of the triangle are in the ratio 3:4:5 and it’s perimeter is 144 cm find its area and height corresponding to the longest side
PLEASE HELP!!!
Evaluate the expression when b=4 and y= -3
-b+2y
Answer: -10
Step-by-step explanation: All you have to do is plug the values into the equation. -4+2(-3). Then you solve the equation using PEDMAS.
1. -4+2(-3)
2. -4+(-6)
3.-4-6
4.-10
Answer:
8
Step-by-step explanation:
-b + 2y
if
b = 4
and
y = 3
then:
-b + 2y = -4 + 2*6 = -4 + 12
= 8
Which phrase represents t times 33 he quotient of a number and 33 the product of a number and 33 the quotient of 33 and a number the difference of a number and 33
Answer:
the product of a number and 33
Step-by-step explanation:
The operation "times" is what is used to form the product of two operands.
"t times 33" is "the product of t and 33"
The size of a television is the length of the diagonal of its screen in inches. The aspect ratio of the screens of older televisions is 4:3, while the aspect ratio of newer wide-screen televisions is 16:9. Find the width and height of an newer 75-inch television whose screen has an aspect ratio of 16:9
Answer:
The Width = 65.44 inches
The Height = 36.81 inches
Step-by-step explanation:
We are told in the question that:
The width and height of an newer 75-inch television whose screen has an aspect ratio of 16:9
Using Pythagoras Theorem we known that:
Width² + Height² = Diagonal²
Since we known that the size of a television is the length of the diagonal of its screen in inches.
Hence, for this new TV
Width² + Height² = 75²
We are given ratio: 16:9 as aspect ratio
Width = 16x
Height = 9x
(16x)² +(9x)² = 75²
= 256x² + 81x² = 75²
337x² = 5625
x² = 5625/337
x² = 16.691394659
x = √16.691394659
x = 4.0855103303
Approximately x = 4.09
For the newer 75 inch tv set
The Height = 9x
= 9 × 4.09
= 36.81 inches
The Width = 16x
= 16 × 4.09
= 65.44 inches.
Given that a random variable X is normally distributed with a mean of 2 and a variance of 4, find the value of x such that P(X < x)
Given that a random variable X is normally distributed with a mean of 2 and a variance of 4, find the value of x such that P(X < x)=0.99 using the cumulative standard normal distribution table
Answer:
6.642
Step-by-step explanation:
Given that mean = 2
standard deviation = 2
Let X be the random Variable
Then X [tex]\sim[/tex] N(n,[tex]\sigma[/tex])
X [tex]\sim[/tex] N(2,2)
By Central limit theorem;
[tex]z = \dfrac{X - \mu}{\sigma} \sim N(0,1)[/tex]
[tex]z = \dfrac{X - 2}{2} \sim N(0,1)[/tex]
P(X<x) = 0.09
[tex]P(Z < \dfrac{X-\mu}{\sigma })= 0.99[/tex]
[tex]P(Z < \dfrac{X-2}{2})= 0.99[/tex]
P(X < x) = 0.99
[tex]P(\dfrac{X-2}{2}< \dfrac{X-2}{2})=0.99[/tex]
[tex]P(Z< \dfrac{X-2}{2})=0.99[/tex]
[tex]\phi ( \dfrac{X-2}{2})=0.99[/tex]
[tex]( \dfrac{X-2}{2})= \phi^{-1} (0.99)[/tex]
[tex]( \dfrac{X-2}{2})= 2.321[/tex]
X -2 = 2.321 × 2
X -2 = 4.642
X = 4.642 +2
X = 6.642
a data set includes 110 body temperatures of healthy adult humans having a mean of 98.1F and a standard deviation of 0.64F. Construct a 99% confidence interval estimate of the mean body temperature of all healthy humans
Answer:
The 99% confidence interval is [tex]97.94 < \mu < 98.26[/tex]
Step-by-step explanation:
From the question we are told that
The sample size is n = 110
The sample mean is [tex]\= x = 98.1 \ F[/tex]
The standard deviation is [tex]\sigma = 0.64 \ F[/tex]
Given that the confidence level is 99% the level of significance i mathematically evaluated as
[tex]\alpha = 100 - 99[/tex]
[tex]\alpha = 1\%[/tex]
[tex]\alpha = 0.01[/tex]
Next we obtain the critical value of [tex]\frac{\alpha }{2}[/tex] from the normal distribution, the values is
[tex]Z_{\frac{\alpha }{2} } = Z_{\frac{0.01 }{2} } = 2.58[/tex]
Generally the margin of error is mathematically represented as
[tex]E = Z_{\frac{\alpha }{2} } * \frac{\sigma}{\sqrt{n} }[/tex]
substituting values
[tex]E = 2.58 * \frac{ 0.64}{\sqrt{110} }[/tex]
[tex]E = 0.1574[/tex]
Generally the 99% confidence interval is mathematically represented as
[tex]\= x - E < \mu < \= x + E[/tex]
substituting values
[tex]98.1 - 0.1574 < \mu < 98.1 + 0.1574[/tex]
[tex]97.94 < \mu < 98.26[/tex]
Answer:
Step-by-step explanation:
Please answer this correctly without making mistakes
Answer:
1,377/2 and 688 1/17
Step-by-step explanation:
The U.S. National Whitewater Center in Charlotte uses a pump station to provide the flow of water necessary to operate the rapids. The pump station contains 7 pumps, each with a capacity to deliver 80,000 gallons per minute (gpm). The water channels and ponds in the facility contain 13 million gallons of water. If the pump station is operating 5 pumps simultaneously, assuming ideal conditions how long will it take to completely pump the volume of the system through the pump station
Answer:
t = 32,5 minutes
Step-by-step explanation:
Volume to fill = 13000000 Gal
5 pumps delivering 80000 gal/min
5 * 80000 = 400000 gal/min
If we divide the total volume by the amount of water delivered for the 5 pumps, we get the required time to fill the volume, then
t = 13000000/ 400000
t = 32,5 minutes
se pueden calcular las edades de Juanita y de su madre si se sabe que:
1) actualmente la suma de sus edades es 44 años
2) dentro de 11 años la edad de juanita será la mitad de la edad de su mamá
Responder:
Juanita = 11, madre = 33
Explicación paso a paso:
Dado lo siguiente:
Suma de sus edades = 44
En 11 años, Juanita tendrá la mitad de la edad de su madre
Sea la edad de la madre = my la edad de juanita = j
m + j = 44 - - - - (1)
(j + 11) = 1/2 (m + 11)
j + 11 = 1/2 m + 5,5; j - 1/2 m = - 5,5; 2j - m = - 11
2j - m = - 11 - - - - (2)
Desde (1): m = 44 - j
Sustituyendo m = 44- j en (2)
2j - (44 - j) = - 11
2j - 44 + j = - 11
3j = - 11 + 44
3j = 33
j = 11
De 1)
m + j = 44
m + 11 = 44
m = 44 - 11
m = 33
more math questions if you would
Answer:
A.
Step-by-step explanation:
So we are given the function:
[tex]f(x)=7x+8[/tex]
To find the inverse of the function, we simply need to flip f(x) and x and then solve for f(x). Thus:
[tex]x=7f^{-1}(x)+8\\x-8=7f^{-1}(x)\\f^{-1}(x)=\frac{x-8}{7}[/tex]
So the answer is A.
Answer:
[tex]\large \boxed{\mathrm{Option \ A}}[/tex]
Step-by-step explanation:
f(x) = 7x+8
Write f(x) as y.
y = 7x + 8
Switch variables.
x = 7y + 8
Solve for y to find the inverse.
x - 8 = 7y
[tex]\frac{x-8}{7}[/tex] = y
