Given that f(x) = x² + 4x, evaluate f(-2).

Answer:

Step-by-step explanation:

The formula for determining the confidence interval for the difference of two population means is expressed as

Confidence interval = (x1 - x2) ± z√(s²/n1 + s2²/n2)

Where

x1 = sample mean of type A paint

x2 = sample mean of type B paint

s1 = sample standard deviation type A paint

s2 = sample standard for type B paint

n1 = number of samples of type A paint

n2 = number of samples of type B paint

From the information given,

x1 = 75.7

s1 = 4.5

n1 = 11

x2 = 64.3

s2 = 5.1

n2 = 9

x1 - x2 = 75.7 - 64.3 = 11.4

√(s1²/n1 + s2²/n2) = √(4.5²/11 + 5.1²/9) = √4.709

Degree of freedom = (n1 - 1) + (n2 - 1)

df = (11 - 1) + (9 - 1) = 18

For the 98% confidence interval, the z score from the t distribution table is 2.552

Margin of error = 2.552√4.709 = 5.55

The upper boundary for the confidence interval is

11.4 + 5.55 = 16.95 hours

The lower boundary for the confidence interval is

11.4 - 5.55 = 5.85 hours

The correct option is

B. 5.85 hrs < μ1 - μ2 < 16.95 hrs

Answer:

(3, -1)

Step-by-step explanation:

5-2=3

0-1=-1 (keep 0, change - to a +, flip 1 to a -1)

Answer:

Radius of the circle = 6 units

Step-by-step explanation:

Let the radius of the circle be r

According to the given condition:

Area of the circle = 3 times the circumference of the circle

[tex]\therefore \pi r^2 =3\times 2\pi r\\\therefore r^2 = \frac{3\times 2\pi r}{\pi}\\\therefore r^2 = 3\times 2r\\\therefore r = 6\: units\\[/tex]

Answer:

1008

Step-by-step explanation:

to find the number of combinations, just multiply everything. you will get 1008 :)

Answer:

39 degrees

Step-by-step explanation:

Given

triangle is right angled i.e one angle is 90 degrees

other angle is 51 degrees.

let the third angle be x degrees

we know that sum of angles of any triangle is 180 degrees

thus,

90 + 51+ x = 180

=> 141 + x = 180

=> x = 180 - 141 = 39.

Thus, measure of other small angle is 39 degrees.

Answer:

Step-by-step explanation:

m∠A+m∠B+m∠C = 180

90+51+x1= 180

41+x=180

x=39

Answer:

24000

Step-by-step explanation:

because 24000 * 10 =240000

Answer:

the answer is 1/2,a0

Step-by-step explanation:

Answer:

x = -6 + [tex]\sqrt{7}[/tex], x = -6 - [tex]\sqrt{7}[/tex]

Step-by-step explanation:

(x + 6)² = 7

x + 6 = + or - [tex]\sqrt{7}[/tex]

x = -6 + [tex]\sqrt{7}[/tex], x = -6 - [tex]\sqrt{7}[/tex]

The solution of the quadratic equation is x = -6 +√7, x = -6 - √7.

A quadratic equation is a polynomial with a degree of 2 or the maximum power of the variable is 2 in quadratic equations. It has two solutions as its maximum power is 2.

Completing the square entails writing a quadratic in the form of a squared bracket and, if necessary, adding a constant. Finding the maximum or minimum value of the function and when it occurs is one application of completing the square.

Given that the quadratic equation is x² + 12x + 36 = 7.

(x + 6)² = 7

x + 6 = ±√7

x = -6 + √7 , x = -6 - √7

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Answer:

c

Step-by-step explanation:

Answer:

37.5

Step-by-step explanation:z

2.0-1.25=0.75

0.75/2.00 x 100

37.5% decrease

Step-by-step explanation:

Hope this helps

Hope this is correct

Answer:

F = 95°

Step-by-step explanation:

[tex]C=\frac{5}{9}(F-32)[/tex] is the formula to convert Fahrenheit to Celsius

If we have C = 35, we just need to plug in this number to its corresponding variable and then solve for F

Answer:

22 m

Step-by-step explanation:

Total distance travelled by marble while falling down = height above surface of lake + depth of lake = 15 + 7 = 22 m

Answer:

Step-by-step explanation:

[tex](x-5)^2+(y-(-3))^2=16[/tex]

Answer:

24 ounces of orange juice

Step-by-step explanation:

Given-

          Calories needed=390 calories

    Calories in 8oz juice=130 calorie

Therefore ounces of juice=(390/130)8

                                          =3 x 8

                                          =24 ounces

If Ronald needs a morning breakfast drink that will give him atleast 390 calories. Orange juice has 130 calories in 8oz. Then 24 ounces does he need to drink to reach his calorie goal.

Two or more expressions with an Equal sign is called as Equation.

Ronald needs a morning breakfast drink that will give him at least 390 calories.

Orange juice has 130 calories in 8oz.

We need to find how many ounces does he need to drink to reach his calorie goal

Calories needed=390 calories

Calories in 8oz juice=130 calorie

Three hundred ninety divided by one hundred thirty times of eight.

Therefore ounces of juice=(390/130)8

Three hundred ninety divided by one hundred thirty is three.

=3 x 8

Three times of eight is twenty four.

=24 ounces

Hence 24 ounces of orange juice does he need to drink to reach his calorie goal.

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Answer:

(a) Probability distribution is prepared below.

(b) The probability that two or fewer heads are observed in three tosses is 0.875.

(c) The probability that at least one head is observed in three tosses is 0.875.

(d) The expected value of X is 1.5.

(e) The standard deviation of X is 2.121.

Step-by-step explanation:

The complete question is: A fair coin is tossed three times. Let X be the number of heads observed in three tosses of this fair coin.

(a) Find the probability distribution of X.

(b) Find the probability that two or fewer heads are observed in three tosses. (Round your answer to three decimal places.)

(c) Find the probability that at least one head is observed in three tosses. (Round your answer to three decimal places.)

(d) Find the expected value of X. (Round your answer to one decimal place.)

(e) Find the standard deviation of X. (Round your answer to three decimal places.)

Now, firstly the sample space obtained in three tosses of a fair coin is given as;

Sample Space (S) = {HHH, HHT, HTH, THH, HTT, TTH, THT, TTT}

(a) The Probability distribution of X is given below;

   Number of Heads (X)         P(X)            [tex]X \times P(X)[/tex]               [tex]X^{2} \times P(X)[/tex]

              0                               [tex]\frac{1}{8}[/tex] = 0.125            0                           0

              1                                [tex]\frac{3}{8}[/tex] = 0.375         0.375                     0.375  

              2                               [tex]\frac{3}{8}[/tex] = 0.375         0.75                          3

              3                               [tex]\frac{1}{8}[/tex] = 0.125          0.375                    3.375

           Total                                                    1.5                        6.75          

(b) The probability that two or fewer heads are observed in three tosses is given by = P(X [tex]\leq[/tex] 2)

      P(X [tex]\leq[/tex] 2) = P(X = 0) + P(X = 1) + P(X = 2)

                     = 0.125 + 0.375 + 0.375

                     = 0.875

(c) The probability that at least one head is observed in three tosses is given by = P(X [tex]\geq[/tex] 1)

      P(X [tex]\geq[/tex] 1) =  1 - P(X = 0)

                    =  1 - 0.125

                    =  0.875

(d) The expected value of X = E(X) =  [tex]\sum (X \times P(X))[/tex]

                                                              =  1.5

(e) The Variance of X = V(X) = [tex]E(X^{2} ) - ( E(X))^{2}[/tex]

                                      =  [tex]\sum (X^{2} \times P(X))- (\sum (X \times P(X)))^{2}[/tex]

                                      =  [tex]6.75 - 1.5^{2}[/tex]  = 4.5

Now, Standard deviation of X = [tex]\sqrt{V(X)}[/tex]

                                                  = [tex]\sqrt{4.5}[/tex]  = 2.121.

Hey there! I'm happy to help!

We want to find out how much Lana pays per month. Let's dissect each payment we are given so we can find our monthly expense.

---------------------------------------------------------------------------

AUTOMOBILE INSURANCE

$300 for automobile insurance semiannually

The prefix semi- means half. Annual means year. So, she is paying $300 every half year, or six months. So, we can divide 300 by 6 to find how much she pays in one month!

300/6=50

Therefore, she pays $50 a month for automobile insurance.

---------------------------------------------------------------------------

HEALTH INSURANCE

We are told here that she pays $100 every month for health insurance. We don't need do anything else here!

---------------------------------------------------------------------------

LIFE INSURANCE

We see that Lana pays $700 per year on life insurance. We can divide this by 12 to find out how much there is in 1 month!

700/12≈58.33

Therefore, she pays $58.33 every month on life insurance.

---------------------------------------------------------------------------

SOLUTION

Now, we just add all of these monthly totals up to find Lana's monthly expense.

50+100+58.33=208.33

Therefore, Lana's monthly expense is $208.33.

I hope that this helps! Have a wonderful day!

Answer:

(D)9.5 Units

Step-by-step explanation:

We have two chords CD and AB intersecting at E.

Using the theorem of intersecting chords

AE X EB =CE X ED

AB=AE+EB

16=10+EB

EB=16-10=6

Therefore:

AE X EB =CE X ED

10 X 6 = 4 X ED

ED =60/4 =15

Therefore:

CD=CE+ED

=4+15

CD=19

Recall that CD is a diameter of the circle and;

Radius =Diameter/2

Therefore, radius of the circle =19/2 =9.5 Units

Answer:

Step-by-step explanation:

Let P=Mount Peak

Let K=Mount Killimanjaro

The equation should then be

12555=P+K    ...1

P=K+765   ... 2

sub equation 2 into 1

12555=P+P+765

12555=2P+765

12555-765=2P+765-765               (subtracting 765 from both sides)

11790=2P

P=5895, now that we know P

we just make a new equation that was similiar to 1

12555=5895+K

K=6660

the height of Mount K is 6660 Metres

Answer:

there is significant distinction in opinion regarding abolition of capital punishment.

Step-by-step explanation:

Compute the p cost of 2-proportion for estimating difference. The Minitab output pronounces the p valu eto be 0.000. This is less than the assumed importance degree of alpha = 0.05. Therefore, reject null hypothesis to finish that there is significant distinction in opinion regarding abolition of capital punishment.

Answer:

a) We want to conduct a hypothesis in order to see if the true mean is 22100 or not, the system of hypothesis would be:  

Null hypothesis:[tex]\mu = 22100[/tex]  

Alternative hypothesis:[tex]\mu \neq 22100[/tex]  

b) We need to find the degrees of freedom given by:

[tex] df =n-1 = 18-1=17[/tex]

And the critical values for this case are:

[tex] t_{\alpha/2}= 2.110[/tex]

c) [tex]t=\frac{23400-22100}{\frac{1412}{\sqrt{18}}}=3.906[/tex]  

d) Since the calculated value is higher than the critical value we have enough evidence to reject the null hypothesis and we can conclude that the true mean is significantly different from 221100 mi

Step-by-step explanation:

Information provided

[tex]\bar X=23400[/tex] represent the sample mean

[tex]s=1412[/tex] represent the sample standard deviation

[tex]n=18[/tex] sample size  

[tex]\mu_o =22100[/tex] represent the value to verify

[tex]\alpha=0.05[/tex] represent the significance level

t would represent the statistic (variable of interest)  

[tex]p_v[/tex] represent the p value

Part a

We want to conduct a hypothesis in order to see if the true mean is 22100 or not, the system of hypothesis would be:  

Null hypothesis:[tex]\mu = 22100[/tex]  

Alternative hypothesis:[tex]\mu \neq 22100[/tex]  

Part b

We need to find the degrees of freedom given by:

[tex] df =n-1 = 18-1=17[/tex]

And the critical values for this case are:

[tex] t_{\alpha/2}= 2.110[/tex]

Part c

The statistic is given by:

[tex]t=\frac{\bar X-\mu_o}{\frac{s}{\sqrt{n}}}[/tex]  (1)  

Replacing the info we got:

[tex]t=\frac{23400-22100}{\frac{1412}{\sqrt{18}}}=3.906[/tex]    

Part d

Since the calculated value is higher than the critical value we have enough evidence to reject the null hypothesis and we can conclude that the true mean is significantly different from 221100 mi

Answer:

Step-by-step explanation:

let the height height of the tree be "h"

Hence the tree's height h=9 ft

one year later,let the height of the tree increased by x ft

hence

[tex]9 + x = 16[/tex] --------This is the equation for the growth of the tree

In order to solve for the added height(growth) of the tree we need to solve for x

[tex]9 + x = 16\\x=16-9\\x=7ft[/tex]

Answer:

The most realistic value for the standard deviation is 15.

Step-by-step explanation:

The standard deviation of a distribution is a measure of dispersion. It is a measure of the spread of the distribution from the mean of the distribution. It expresses how far most of the distribution is from the mean.

Mathematically, the standard deviation is given as the square root of variance. And variance is an average of the squared deviations from the mean.

Mathematically,

Standard deviation = σ = √[Σ(x - xbar)²/N]

x = each variable (ranges from 34 to 99)

xbar = mean = 78

N = number of variables

Now taking the given possible values of the standard deviation one at a time,

-14

The standard deviation cannot be negative as it is a square root of the average of the sum of square deviations from the mean. Since the square of a number cannot be negative, it directly translates that the standard deviation cannot be negative.

3

A small standard deviation like 3 indicates that the distribution mostly centres about the mean, with very little variation. And the distribution given has a mean (78) that is very far away from at least one of the variables in the distribution. Hence, 3 is too low to pass ad the standard deviation of this distribution described.

0

A standard deviation of 0 indicates that all the variables in the distribution have the same value as the mean. That is, the distribution only contains 1 number, probably multiple times. So, this cannot be the standard deviation for the distribution described.

56

This value represents a value that is too high to express the spread of the distribution described. The mean (78) is very close to the maximum value of the distribution, and far away from the lower value(s), indicating that most of the distribution is in and around the upper values with a few variables closer to the lower limit. A standard deviation as high as 56 for a mean of 78 translates to a distribution with most of variables far from the mean, which isn't the case here.

Moreso, a simple add of the standard deviation to the mean or subtracting the standard deviation from the mean should give at least one of the results with values within the distribution.

(Mean) + (Standard deviation) = 78 + 56 = 134 >> 99 (outside distribution)

(Mean) + (Standard deviation) = 78 - 56 = 22 << 34 (also outside the distribution)

15

This is the most realistic value for the standard deviation as it represents what the distribution described above is.

The mean (78) being close to the maximum value of the distribution, and far away from the lower value(s) indicates that most of the distribution is in and around the upper values with a few variables closer to the lower limit.

So, 15 indicates a perfect blend of small deviations due to the high values close to the mean and the very high deviation from the evidently few lower values.

(Mean) + (Standard deviation) = 78 + 15 = 93 < 99 (within distribution)

(Mean) + (Standard deviation) = 78 - 15 = 63 > 34 (also within the distribution)

Hope this Helps!!!

When The most realistic value for the standard deviation is 15.

Step-by-step explanation:

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Answer:50%

Step-by-step explanation:670/1340 = 1/2 = 50%

Answer:

28 and 7

35

Step-by-step explanation:

The area of a triangle is base*height/2, no matter the shape.

So the big one is 8*7/2 = 28 in²

And the little one is 2*7/2 = 7 in²

The total trapezoid therefore has an area of 28+7=35 in²

Step-by-step explanation:

1039

This is the correct answer

Answer:

y=[x+1]-3 because it's at the end of the line

Answer:

The correct answer is B (24 units)

Step-by-step explanation:

Answer:

€ 270

Step-by-step explanation:

Since the production cost C(x,y) = 2x² + 5y² + 120 is less than or equal to 250, we have  2x² + 5y² + 120 ≤ 250

The selling price S(x,y) = 40x + 80y

The profit P(x,y) = S(x,y) - C(x,y) = 40x + 80y - 2x² - 5y² - 120

Using the principle of lagrange multipliers, we want to maximize the profit P(x,y) under the condition that C(x.y) ≤ 250.

So, dP/dx = 40 - 4x , dC/dx = 4x, dP/dy = 80 - 10y , dC/dy = 10y

dP/dx + λdC/dx = 0

40 - 4x + 4λx = 0  (1)

4λx = 4x - 40

λ = (x - 10)/x

dP/dy + λdC/dy = 0

80 - 10y + 10λy = 0 (2)

substituting λ into (2), we have

80 - 10y + 10(x - 10)y/x = 0

multiplying through by x, we have

80x - 10xy + 10xy - 100y = 0

80x - 100y = 0

80x = 100y

x = 100y/80

x = 5y/4

substituting x into C(x,y) ≤ 250, we have

2(5y/4)² + 5y² + 120 ≤ 250

25y²/8 + 5y² + 120 ≤ 250

25y² + 40y² + 960 ≤ 2000

65y² ≤ 2000 - 960

65y² ≤ 1040

y² ≤ 1040/65

y² ≤ 16

y ≤ ±√16

y ≤ ± 4 since its quantity, we take the positive value.

So x = 5y/4 = 5(± 4)/4 = ± 5

So, x ≤ ± 5

For the maximum value for the profit, P(x,y), we take the maximum values of x and y which are x = 5 and y = 4. Substituting these values into P(x,y), we have

P(5,4) = 40(5) + 80(4) - 2(5)² - 5(4)² - 120

= 200 + 320 - 50 - 80 - 120

= 520 - 250

= 270

So, the maximum profit obtained is € 270

Answer:

option 2

Step-by-step explanation:

Because (0, 900) is a point on the line it means that it costs $900 to make the commercial. A slope of 110 means that they pay $110 every time it's aired so the answer is Option 2.

Answer:

A. 1.5 seconds

B. 36 feet

C. 0 feet

D. After 3 seconds

Step-by-step explanation:

I graphed it on desmos.