Please answer this correctly

Answer:

Step-by-step explanation:

1) Point estimate is the difference between the sample means. Therefore,

A point estimate for the difference between the mean purchases of the users of the two credit cards is = 140 - 125 = $15

2) Margin of error = z√(σ²/n1 + σ2²/n2)

Where

z is the z score from the 95% confidence level. From the normal distribution table, z = 1.96

s1 and s2 are standard deviation for both customers respectively.

Standard deviation = √variance

σ1 = √100 = 10

σ2 = √641 = 25.32

Margin of error = 1.96√(10²/64 + 25.32²/49 = 7.5

At 95% confidence, the margin of error is 7.5

3) The confidence interval for the difference of two population means is expressed as point estimate ± margin of error

Confidence interval = 15 ± 7.5

The upper boundary for the confidence interval is

15 - 7.5 = 7.5

The lower boundary for the confidence interval is

15 + 7.5 = 22.5

A 95% confidence interval estimate for the difference between the average purchases of the customers using the two different credit cards is $7.5 to $22.5

4) Since the population standard deviations are known, we would use the formula to determine the test statistic(z score)

z = (x1 - x2)/(√σ1²/n2 + σ2²/n2)

z = (140 - 125)/√10²/64 + 25.32²/49

z = 1.02

The test statistic for an alpha of .05 is 1.02

Answer:

150 km

Step-by-step explanation:

1 liter ............ 40 km

15/4 liter .........x km

x = 15/4×40/1 = 600/4 = 150 km

Answer:

x = 90

y = 100

z = -10

Step-by-step explanation:

To find x and y in the above parallelogram ABCD as shown above, recall that one of the properties of a parallelogram is: the consecutive angles in a parallelogram are supplementary.

This means that the sum of angle A and angle B in the parallelogram ABCD = 180°.

Thus,

(x + 30)° + (x - 30)° = 180°

Solve for x

x + 30 + x - 30 = 180

x + x + 30 - 30 = 180

2x = 180

Divide both sides by 2

2x/2 = 180/2

x = 90

=>Find y:

Also, recall that opposite angles in a parallelogram are congruent.

This means, angle A and angle C in parallelogram ABCD above are equal.

Thus,

(x + 30)° = (y + 20)°

Plug in the value of x to solve for y

90 + 30 = y + 20

120 = y + 20

Subtract 20 from both sides

120 - 20 = y

100 = y

y = 100

=>Find z, if z = x - y

z = 90 - 100

z = -10

Answereippcb.jrc.ec.europa.eu

Step-by-step explanation:

this I the wed go on it and you will get your answer

Answer:

(B)[tex]\dfrac{dA}{dt}=8-0.004A[/tex]

Step-by-step explanation:

Volume of fluid in the tank =1000 gallons

Initial Amount of Salt in the tank, A(0)= 30 pounds

Incoming brine solution of concentration 2 pounds of salt per gallon is pumped in at a rate of 4 gallons per minute.

Rate In=(concentration of salt in inflow)(input rate of brine)

[tex]=(2\frac{lbs}{gal})( 4\frac{gal}{min})=8\frac{lbs}{min}[/tex]

The resulting mixture is pumped out at the same rate, therefore:

Rate Out =(concentration of salt in outflow)(output rate of brine)

[tex]=(\frac{A(t)}{1000})( 4\frac{gal}{min})=\frac{A}{250}[/tex]

Therefore:

The rate of change of amount of salt in the tank,

[tex]\dfrac{dA}{dt}=$Rate In-Rate out\\\dfrac{dA}{dt}=8-\dfrac{A}{250}\\\dfrac{dA}{dt}=8-0.004A[/tex]

Answer:

144

Step-by-step explanation:

Susan can pick 4 pounds of coffee beans in an hour.  Tom can pick 2 pounds of coffee beans in an hour.  Together, they can pick 6 pounds of coffee an hour.

4 + 2 = 6

There are 24 hours in a day.  Multiply the time by the amount that can be picked to find the answer.

24 × 6 = 144

Together, the maximum number of pounds of coffee beans the can pick in a day is 144 pounds.

Together they can pick a maximum of 36 pounds of coffee

The unitary method is a technique for solving a problem by first finding the value of a single unit, and then finding the necessary value by multiplying the single unit value.

given:

Susan can pick 4 pounds of coffee or 2 pounds of nuts.

Tom can pick 2 pounds of coffee or 4 pounds of nuts.

So, In 6 hours

Susan will pick

= 4 * 6

= 24 pounds of coffee.

In 6 hours,

Tom will pick

=2 * 6

= 12 pounds of coffee.

Hence, together they can pick a maximum of 36 pounds of coffee

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Answer:

0.001

Step-by-step explanation:

Here, the aim is to support the null hypothesis, Ha. Where Ha: p > 0.5. Which means we are to reject null hypothesis H0. Where H0: p = 0.5.

The higher the pvalue, the higher the evidence of success. We know If the pvalue is less than level of significance, the null hypothesis H0 is rejected.

Hence the smallest possible value 0.001 is preferred as the pvalue because it corresponds to the sample evidence that most strongly supports the alternative hypothesis that the method is effective

Answer:

The probability that the mean of my sample will be between 24 and 25 cm

P(24 ≤X⁻≤25) = 0.4772

Step-by-step explanation:

Step(i):-

Given mean of the Population  'μ'= 25c.m

Given standard deviation of the Population 'σ' = 8c.m

Given sample size 'n' = 256

Let X₁ = 24

[tex]Z_{1} = \frac{x_{1}-mean }{\frac{S.D}{\sqrt{n} } } = \frac{24-25}{\frac{8}{\sqrt{256} } } = -2[/tex]

Let X₂ = 25

[tex]Z_{2} = \frac{x_{2}-mean }{\frac{S.D}{\sqrt{n} } } = \frac{25-25}{\frac{8}{\sqrt{256} } } = 0[/tex]

Step(ii):-

The probability that the mean of my sample will be between 24 and 25 cm

P(24 ≤X⁻≤25) = P(-2≤ Z ≤0)

                     = P( Z≤0) - P(Z≤-2)

                     = 0.5 + A(0) - (0.5- A(-2))

                     = A(0) + A(2)        ( ∵A(-2) =A(2)

                     = 0.000+ 0.4772

                     = 0.4772

Final answer:-

The probability that the mean of my sample will be between 24 and 25 cm

P(24 ≤X⁻≤25) = 0.4772

Answer:

Step-by-step explanation:

When two variables vary inversely, it means that an increase in one would lead to a decrease in the other and vice versa. Since the volume of a gas, V in a container varies inversely with the pressure on the gas, P, if we introduce a constant of proportionality, k, the expression would be

V = k/P

If V = 370 in³ and P = 15psi, then

370 = k/15

k = 370 × 15 = 5550

The equation that relates the volume, V, to the pressure, P would be

V = 5550/P

if the pressure was increased to 25psi, the volume would be

V = 5550/25 = 222 in³

Answer:

v=5550/p

222

Step-by-step explanation:

Answer:

n > 1700

Step-by-step explanation:

n ÷ 4 – 125 > 300

Add 125 to both sides.

n ÷ 4 > 425

Multiply both sides by 4.

n > 1700

Answer:

n > 1700

Step-by-step explanation:

n ÷ 4 - 125 > 300

Add 125 to both parts.

n ÷ 4 > 300 + 125

n ÷ 4 > 425

Multiply both sides with 4.

n > 425 × 4

n > 1700

Answer:

66.992%

Step-by-step explanation:

[tex]Sales, S(t)=7-6\sqrt[3]{t}[/tex]

Since we want to maximize revenue for the government

Government's Revenue= Sales X Tax Rate

[tex]R(t)=t \cdot S(t)\\R(t)=t(7-6\sqrt[3]{t})\\=7t-6t^{1+1/3}\\R(t)=7t-6t^{4/3}[/tex]

To maximize revenue, we differentiate R(t) and equate it to zero to solve for its critical points. Then we test that this critical point is a relative maximum for R(t) using the second derivative test.

Now:

[tex]R'(t)=7-6*\frac{4}{3} t^{4/3-1}\\=7-8t^{1/3}[/tex]

Setting the derivative equal to zero

[tex]7-8t^{1/3}=0\\7=8t^{1/3}\\t^{1/3}=\dfrac{7}{8} \\t=(\frac{7}{8})^3\\t=0.66992[/tex]

Next, we determine that t=0.6692 is a relative maximum for R(t) using the second derivative test.

[tex]R''(t)=-8*\frac{1}{3} t^{1/3-1}\\R''(t)=-\frac{8}{3} t^{-2/3}[/tex]

R''(0.6692)=-3.48 (which is negative)

Therefore, t=0.66992 is a relative maximum for R(t).

The tax rate, t that maximizes revenue for the government is:

=0.66992 X 100

t=66.992% (correct to 3 decimal places)

Step-by-step explanation: To write a fraction as a percent, first remember that a percent is a ratio of a number to 100.

So to write 3/7 as a percent, we need to find a fraction

equivalent to 3/7 that has a 100 in the denominator.

We can do this by setting up a proportion.

So we have [tex]\frac{3}{7} = \frac{n}{100}[/tex].

Now, we can use cross-products to find the missing value.

So we have (3)(100) which is 300 is equal to (7)(n) or 7n.

So we have the equation 300 = 7n.

Next, dividing both sides of the equation by 7, we have 42.8571 = n.

So 3/7 is equal to 42.8571/100 or 42.8571%.

Answer:

r = (An−nP)/P

Step-by-step explanation:

A = P(1 + nr)

Divide P on both sides.

A/P = 1 + nr

Subtract 1 on both sides.

A/P - 1 = nr

Divide n on both sides.

A/P/n - 1/n = r

(An−nP)/P = r

The answer is, r = (An−nP)/P

An equation is a  mathematical statement that is made up of two expressions connected by an equal sign.

here, we have,

given that,

A = P(1 + nr)

Divide P on both sides.

A/P = 1 + nr

Subtract 1 on both sides.

A/P - 1 = nr

Divide n on both sides.

A/P/n - 1/n = r

(An−nP)/P = r

hence, answer is (An−nP)/P = r.

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Answer:

Step-by-step explanation:

[tex]\sqrt{-16}=\sqrt{16i^{2}}\\\\ =\sqrt{4^{2}*i^{2}}\\\\=4i[/tex]

Answer:

1/9

Step-by-step explanation:

The probability of picking a even number is 1/3

The probability of picking another even number is 1/3(if u put the first one back)

So u multiply 1/3 times 1/3 which gives u 1/9 which is ur answer hope this helps

Answer:

1/9

Step-by-step explanation:

3 cards total

1 even number

P(even) = even/total

                1/3

Put the card back

3 cards total

1 even number

P(even) = even/total

                1/3

P(even, replace, even) = P(even) * P(even) =1/3*1/3 = 1/9

Answer:

domain: (-4,4)

Step-by-step explanation:

i'm not sure if it has brackets because it doesn't have point that are on x-intervals -4 and 4

Answer:

Decreases by 2 degrees

Step-by-step explanation:

The expression that describes temperature as a function of latitude is:

[tex]T=110-2(Latitude)[/tex]

This equation represents a linear relationship between latitude and temperature in a way that an increase in latitude causes a decrease in temperature. The magnitude of this decrease is quantified by the slope of the linear equation, which is -2. Therefore, the estimated temperature decreases by 2 degrees when latitude is increased by one.

Answer:

Step-by-step explanation:

33.3%

19.4%

Answer:

The expected value is also known as the expectation, mathematical expectation, mean, average, or first moment.

Answer:

2.24 s

Step-by-step explanation:

Given:

Δy = 80 ft

v₀ = 0 ft/s

a = 32 ft/s²

Find: t

Δy = v₀ t + ½ at²

80 ft = (0 ft/s) t + ½ (32 ft/s²) t²

t = 2.24 s

Answer:54

volume:side*side*side

side:1 cm*1 cm *1 cm      

answer=icm

Answer:

50%

Step-by-step explanation:

There are 3 numbers fitting the rule, 1, 2, and 6. There is a 3/6 chance rolling one of them or 50%.

Answer:

50%

Step-by-step explanation:

1 value> 5 and 2 values<3, out of total of 6

P (greater than 5 or less than 3) = 3/6= 50%

Answer:

The correct answer would be C

Step-by-step explanation:

please mark brainliest

The choice which best compares the volume of the cylinders is; Choice B; The volume of cylinder B is the same as that of cylinder A.

From geometry, It can be concluded that the volume of a solid shape is the product of its cross sectional area and the height over which the area spans. On this note, since the volume of a cylinder is dependent on the radius and height of the cylinder, both cylinders have equal volumes.

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Answer:

a. The 95% confidence interval for the mean is (33.52, 35.48).

b. The 95% confidence interval for the mean is (34.02, 34.98).  

c. n=49 ⇒ Width = 1.95

n=196 ⇒ Width = 0.96

Note: it should be a factor of 2 between the widths, but the different degrees of freedom affects the critical value for each interval, as the sample size is different. It the population standard deviation had been used, the factor would have been exactly 2.

d. 5. Quadrupling the sample size while holding the confidence coefficient fixed decreases the width of the confidence interval by a factor of 2.

Step-by-step explanation:

a. We have to calculate a 95% confidence interval for the mean.

The population standard deviation is not known, so we have to estimate it from the sample standard deviation and use a t-students distribution to calculate the critical value.

The sample mean is M=34.5.

The sample size is N=49.

When σ is not known, s divided by the square root of N is used as an estimate of σM:

[tex]s_M=\dfrac{s}{\sqrt{N}}=\dfrac{3.4}{\sqrt{49}}=\dfrac{3.4}{7}=0.486[/tex]

The degrees of freedom for this sample size are:

[tex]df=n-1=49-1=48[/tex]

The t-value for a 95% confidence interval and 48 degrees of freedom is t=2.011.

The margin of error (MOE) can be calculated as:

[tex]MOE=t\cdot s_M=2.011 \cdot 0.486=0.98[/tex]

Then, the lower and upper bounds of the confidence interval are:

[tex]LL=M-t \cdot s_M = 34.5-0.98=33.52\\\\UL=M+t \cdot s_M = 34.5+0.98=35.48[/tex]

The 95% confidence interval for the mean is (33.52, 35.48).

b. We have to calculate a 95% confidence interval for the mean.

When σ is not known, s divided by the square root of N is used as an estimate of σM:

[tex]s_M=\dfrac{s}{\sqrt{N}}=\dfrac{3.4}{\sqrt{196}}=\dfrac{3.4}{14}=0.243[/tex]

The degrees of freedom for this sample size are:

[tex]df=n-1=196-1=195[/tex]

The t-value for a 95% confidence interval and 195 degrees of freedom is t=1.972.

The margin of error (MOE) can be calculated as:

[tex]MOE=t\cdot s_M=1.972 \cdot 0.243=0.48[/tex]

Then, the lower and upper bounds of the confidence interval are:

[tex]LL=M-t \cdot s_M = 34.5-0.48=34.02\\\\UL=M+t \cdot s_M = 34.5+0.48=34.98[/tex]

The 95% confidence interval for the mean is (34.02, 34.98).

c. The width of the intervals is:

[tex]n=49\rightarrow UL-LL=33.52-35.48=1.95\\\\n=196\rightarrow UL-LL=34.02-34.98=0.96[/tex]

d. The width of the intervals is decreased by a factor of √4=2 when the sample size is quadrupled, while the others factors are fixed.

Answer:

A.  A = 8h + 10

     A = 10h

B.  5 hours

C.  $50

Step-by-step explanation:

A.  https://brainly.com/question/17036764

Pizza Place:  A = 8h + 10

Hardware Store:  A = 10h

Since you had made a separate question for part A, I answered that.

B.  Kevin's earnings is represented by A.  Because we want the earnings for each job to be equal, set the two equations equal to each other.  Solve for h.

8h + 10 = 10h

10 = 2h

5 = h

Kevin has to work 5 hours.

C.  Plug 5 into each equation.

A = 8h + 10

A = 8(5) + 10

A = 40 + 10

A = 50

A = 10h

A = 10(5)

A = 50

Kevin will make 50 from each job.

Answer:

Two Portions!!!

Step-by-step explanation:

Answer:

(B)24 Units

Step-by-step explanation:

Triangle MNO is an equilateral triangle with sides  measuring [tex]16\sqrt{3}[/tex] units.

The height divides the base into two equal parts of lengths [tex]8\sqrt{3}[/tex] units.

As seen in the diagram, we have a right triangle where the:

Using Pythagoras Theorem

[tex](16\sqrt{3})^2=(8\sqrt{3})^2+h^2\\16^2*3-8^2*3=h^2\\h^2=576\\h=\sqrt{576}\\ h=24$ units[/tex]

The height of the triangle is 24 Units.

The height of the given equilateral triangle is gotten as;

B: 24 units

Equilateral Triangles

The height of an equilateral triangle starts from the mid - point of the base to the ap ex.

Now, if the sides of the equilateral triangle are 16√3 units, then it means we can use pythagorean theorem to find the height h.

Half of the base will be; ¹/₂ * 16√3 = 8√3

Thus, the height h can be calculated from;

h²= ((16√3)² - (8√3)²)

h² = 3(256 - 64)

h² = 576

h = √576

h = 24 units

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Answer:

yes

Step-by-step explanation:

y = 19+ 3x

Let x = 3 and y = 28

28 = 19 + 3*3

28 =19+9

28 = 28

This is true so the point is one the line

Answer: your answer should be 103

Answer:

Step-by-step explanation:

103

Complete Question:

You want to install a 1 yd wide walk around a circular swimming pool. The diameter of the pool is 23 yd. What is the area of the​ walk? Use 3.14 for pi π.

Answer:

75.36 square yard

Step-by-step explanation:

From the question,

The diameter of this circular pool inside is 23 yd.

This means that the radius = Diameter/2 = 23yd/2 = 11.5 yd.

The formula for the area of a circle =

A = πr²

A = π(11.5)²

A =3.14 × 11.5²

A = 415.265 yd²

This is the Area of the inner circle.

We were told in the question also that he wants to install a walk of 1 yard

Hence, the radius of outer circle =

radius of inner circle +length of the walk

11.5yard + 1 yard

= 12.5 yard

A = πr²

A = 3.14 × (12.5)²

A = 490.625yd²

Area of the walk = Area of the Outer circle - Area of the inner circle

= (490.625 - 415.265)yd = 75.36 yd²

Therefore, the area of the walk is 75.36 square yards.