please help me... I'm confused​

Answer:

Step-by-step explanation:

The exponential function for growth/decay is given as:

[tex]P(t)=P_0(1 \pm r)^t, where:\\P_0$ is the Initial Population\\r is the growth/decay rate\\t is time[/tex]

In this problem:

The city's initial population is 120,000 and it decreases by 1.4% per year.

Therefore, the function is:

[tex]P(t)=120000(1 - 0.014)^t\\P(t)=120000(0.986)^t[/tex]

When t=10 years

[tex]P(10)=120000(0.986)^10\\=104219.8\\\approx 104220 $ (to the nearest whole number)[/tex]

Answer:

(B) 0.7%

Step-by-step explanation:

X = Land Elevation (in ,000 feet)

Y = Unidentified Artifacts (in %)

The hypothetical theory says that:

The higher the elevation, the higher the percentage of unidentified artifacts in the location.

To find the percentage of variation in Y that can be explained by variations in X, we find the slope of the graph of X on Y.

Transforming X to thousand feets, we have 5220, 5690, 6250, 6750, 7250. This is in the attachment, plotted against 17, 12, 33, 37 and 62 respectively.

Further calculations, along with the graph, are in the attachment below. The answer therein is (B) 0.7%

Answer:

The perimeter is

Step-by-step explanation:

perimeter is the whole distance you will go around the shape

Perimeter= 19 +3+(19-5)+(8-3)+5+8

= 19+3+14+5+5+8

= 54

For area, cut the triangle into small and big rectangle

Area = 19 * 3+ (8-3) * 5

= 57 + 25

= 82

Answer:

180 or 1260

Step-by-step explanation:

4*5=20

8*2=16

20+16=36

36*5=180

180*7=1260

sorry it took so long im only in 8th grade but im doing 11th grade classes because im smart i guess

[tex]answer = 66 \: {cm}^{3} \\ solution \\ volume = lwh \\ \: \: \: \: \: \: \: \: \: \: = \: 11 \times 3 \times 2 \\ \: \: \: \: \: \: \: \: \: = 66 \: {cm}^{3} \\ hope \: it \: helps \\ good \: luck \: on \: your \: assignment[/tex]

Answer:

[tex]= 66 {cm}^{3} \\ [/tex]

Step-by-step explanation:

[tex]volume = base \times length \times height \\ = 3cm \times 11cm \times 2cm \\ = 66 {cm}^{3} [/tex]

hope this helps

brainliest appreciated

good luck! have a nice day!

Answer:

480

Step-by-step explanation:

Answer:

x = sqrt(5)/2 - 1/2 or x = -1/2 - sqrt(5)/2

Step-by-step explanation:

Solve for x over the real numbers:

x - 2 + x/x + 1 - 1/x = -1

x - 2 + x/x + 1 - 1/x = x - 1/x:

x - 1/x = -1

Bring x - 1/x together using the common denominator x:

(x^2 - 1)/x = -1

Multiply both sides by x:

x^2 - 1 = -x

Add x to both sides:

x^2 + x - 1 = 0

Add 1 to both sides:

x^2 + x = 1

Add 1/4 to both sides:

x^2 + x + 1/4 = 5/4

Write the left hand side as a square:

(x + 1/2)^2 = 5/4

Take the square root of both sides:

x + 1/2 = sqrt(5)/2 or x + 1/2 = -sqrt(5)/2

Subtract 1/2 from both sides:

x = sqrt(5)/2 - 1/2 or x + 1/2 = -sqrt(5)/2

Subtract 1/2 from both sides:

Answer: x = sqrt(5)/2 - 1/2 or x = -1/2 - sqrt(5)/2

Answer:

32 cm²

Step-by-step explanation:

6*4+ 1/2*4*4= 32 cm²

Answer:

the first option

Step-by-step explanation:

Sum means addition so the sum of 9 and half a number is 9 + 1/2x. The only answer option that has this on the left side is the first option.

Answer:

So the answer is going to be B. AKA 22.5

Step-by-step explanation:

I took the test on ed and got this answer right! hth (hope this helps)

Answer:

B, second option, 22.5

Step-by-step explanation:

1.)because

2.)i'm

3.)kinda

4.)smart

answer=22.5:))))))))

Answer: The answer is 19

Step-by-step explanation:

Answer:

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

And we can use the probability mass function and we got:

[tex]P(X=0)=(4C0)(0.72)^0 (1-0.72)^{4-0}=0.00615[/tex]

And replacing we got:

[tex] P(X \geq 1) = 1-0.00615 = 0.99385[/tex]

Step-by-step explanation:

Let X the random variable of interest "number of graduates who enroll in college", on this case we now that:  

[tex]X \sim Binom(n=4, p=0.72)[/tex]  

The probability mass function for the Binomial distribution is given as:  

[tex]P(X)=(nCx)(p)^x (1-p)^{n-x}[/tex]  

Where (nCx) means combinatory and it's given by this formula:  

[tex]nCx=\frac{n!}{(n-x)! x!}[/tex]  

We want to find the following probability:

[tex] P(X \geq 1)[/tex]

And we can use the complement rule and we got:

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

And we can use the probability mass function and we got:

[tex]P(X=0)=(4C0)(0.72)^0 (1-0.72)^{4-0}=0.00615[/tex]

And replacing we got:

[tex] P(X \geq 1) = 1-0.00615 = 0.99385[/tex]

Answer:

Step-by-step explanation:

a) Number of variables in the data set : 5

b) A quantitative variable is the one which can be quantitatively measured. i.e. it is a numerical value.

A categorical variable is the one that can take one value from a limited number of fixed values.

Exchange is a Categorical Variable. Price/Earnings Ratio is a Quantitative Variable. Gross Profit Margin (%) is a Quantitative Variable.

c. Out of the 25 stocks, AMEX is the exchange for 5 stocks. So percent frequency is 5/25 = 0.2 = 20%.

NYSE is the exchange for 3 stocks. So percent frequency is 3/25 = 0.12 = 12%.

OTC is the exchange for 17 stocks. So percent frequency is 17/25 = 0.68 = 68%.

These percentages are correctly shown in graph a. So the answer is a.

d) The frequency distribution is

Gross Profit Margin                Frequency

0-14.9                                        2

15-29.9                                      6

30-44.9                                     8

45.59.9                                    6

60.74.9                                    3

As we come across the Gross Profit Margin values in the table, we add a | next to its respective interval and build the above table. E.g. the first value in the table under Gross Profit Margin is 36.7 which lies in the interval 30–44.9. So we add one | in fromt of that interval and so on until we cover the entire table. The number of | shows the frequency distribution of the values.

The correct histogram is A.

e. The average price/earnings ratio is found by adding all the 25 values in the table and dividing the answer by 25.

= 505.40/25

Answer:

c>-13/10

Step-by-step explanation:

55c+13<75c+39

55c+13-75c<39

-20c+13<39

-20c<39-13

-20c<26

c>26/-20

c>-13/10

Answer:

6.2 × 10⁵

Step-by-step explanation:

Move the decimal so there is one non-zero digit to the left of the decimal point. The number of decimal places you move will be the exponent on the 10.

If the decimal is being moved to the right, the exponent will be negative. If the decimal is being moved to the left, the exponent will be positive.

Step-by-step explanation:

Simplifying

f(x) = 2cos(3x)

Multiply f * x

fx = 2cos(3x)

Remove parenthesis around (3x)

fx = 2cos * 3x

Reorder the terms for easier multiplication:

fx = 2 * 3cos * x

Multiply 2 * 3

fx = 6cos * x

Multiply cos * x

fx = 6cosx

Solving

fx = 6cosx

Solving for variable 'f'.

Move all terms containing f to the left, all other terms to the right.

Divide each side by 'x'.

f = 6cos

Simplifying

f = 6cos

Answer:

She can answer, after performing the hypothesis test, that there is not enough evidence to support the claim that the city firefighters salary is significantly lower than the national average.

Step-by-step explanation:

She can statistically test the claim of the firefighters to see if it has statistical evidence.

This is a hypothesis test for the population mean.

The claim is that the city firefighters salary is significantly lower than the national average.

Then, the null and alternative hypothesis are:

[tex]H_0: \mu=38202\\\\H_a:\mu< 38202[/tex]

The significance level is 0.1.  Is less conservative than 0.05, for example, so if there is little evidence, the null hypothesis with be rejected.

The sample has a size n=27.

The sample mean is M=38073.

As the standard deviation of the population is not known, we estimate it with the sample standard deviation, that has a value of s=575.

The estimated standard error of the mean is computed using the formula:

[tex]s_M=\dfrac{s}{\sqrt{n}}=\dfrac{575}{\sqrt{27}}=110.659[/tex]

Then, we can calculate the t-statistic as:

[tex]t=\dfrac{M-\mu}{s/\sqrt{n}}=\dfrac{38073-38202}{110.659}=\dfrac{-129}{110.659}=-1.17[/tex]

The degrees of freedom for this sample size are:

df=n-1=27-1=26

This test is a left-tailed test, with 26 degrees of freedom and t=-1.17, so the P-value for this test is calculated as (using a t-table):

[tex]\text{P-value}=P(t<-1.17)=0.127[/tex]

As the P-value (0.127) is bigger than the significance level (0.1), the effect is not significant.

The null hypothesis failed to be rejected.

There is not enough evidence to support the claim that the city firefighters salary is significantly lower than the national average.

Answer:

Step-by-step explanation:

0.00039 hm

Answer:

0.00039 hm is ur answer....

3.9 cm to 0.00039 hm...

Mark me as Brainlist...

Answer:

The answer is C, 3/4.

Since it is parallel to y=3/4 x+2, 3/4 is the slope for both equations.

Answer:

(10, 11, 12, 13, 14, 15, 16)

Step-by-step explanation:

The minimum number of tables that the store has to sell in order to meet the requirements is given by:

[tex](25-t)*100+t*550=7,000\\(550-100)t=7,000-2,500\\t = 10\ tables[/tex]

The company must sell at least 10 tables.

Since the company already sold 9 chairs, and they can ship at most 25 items, they can sell at most 16 tables. Every integer number between the minimum and maximum is also possible:

(10, 11, 12, 13, 14, 15, 16).

Answer:

12,13,14,15,16

Step-by-step explanation:

\underline{\text{Define Variables:}}

Define Variables:

​

May choose any letters.

\text{Let }t=

Let t=

\,\,\text{the number of tables sold}

the number of tables sold

\text{Let }c=

Let c=

\,\,\text{the number of chairs sold}

the number of chairs sold

\text{\textquotedblleft at most 25 pieces"}\rightarrow \text{25 or fewer pieces}

“at most 25 pieces"→25 or fewer pieces

Use a \le≤ symbol

Therefore the total number of furniture pieces sold, t+ct+c, must be less than or equal to 25:25:

t+c\le 25

t+c≤25

\text{\textquotedblleft no less than \$7000"}\rightarrow \text{\$7000 or more}

“no less than $7000"→$7000 or more

Use a \ge≥ symbol

The store makes $550 for each table sold, so for tt tables, the store will make 550t550t dollars. The store makes $100 for each chair sold, so for cc chairs, the store will make 100c100c dollars. Therefore, the total revenue 550t+100c550t+100c must be greater than or equal to \$7000:$7000:

550t+100c\ge 7000

550t+100c≥7000

\text{Plug in }9\text{ for }c\text{ and solve each inequality:}

Plug in 9 for c and solve each inequality:

The store sold 9 chairs

\begin{aligned}t+c\le 25\hspace{10px}\text{and}\hspace{10px}&550t+100c\ge 7000 \\ t+\color{green}{9}\le 25\hspace{10px}\text{and}\hspace{10px}&550t+100\left(\color{green}{9}\right)\ge 7000 \\ t\le 16\hspace{10px}\text{and}\hspace{10px}&550t+900\ge 7000 \\ \hspace{10px}&550t\ge 6100 \\ \hspace{10px}&t\ge 11.09 \\ \end{aligned}

t+c≤25and

t+9≤25and

t≤16and

​

550t+100c≥7000

550t+100(9)≥7000

550t+900≥7000

550t≥6100

t≥11.09

​

\text{The values of }t\text{ that make BOTH inequalities true are:}

The values of t that make BOTH inequalities true are:

\{12,\ 13,\ 14,\ 15,\ 16\}

{12, 13, 14, 15, 16}

\text{(the final answer is this entire list)}

(the final answer is this entire list)

Answer:

The answer is C

Step-by-step explanation:

did the quiz

Answer:

He is right it C just did the quiz let him have the brainly ;)

Step-by-step explanation:

Answer:

C) 8

Step-by-step explanation:

By remote interior angle property of a triangle.

[tex] 19x - 3 = 94° + 7x - 1\\\\

19x - 7x = 94 + 3 - 1\\\\

12 x = 96\\\\

x = \frac{96}{12}\\\\

\huge \orange{\boxed {x = 8}} [/tex]

Answer:

$8.5

Step-by-step explanation:

We need to propose a system of equations with the information provided to us.

two large pizzas and one small pizza cost $36:

[tex]2L+S=36[/tex]

where

[tex]L[/tex]: Large pizza

[tex]S:[/tex] Small pizza

and the difference in cost between a large and small pizza is $5.25:

[tex]L-S=5.25[/tex]

our system of equations is:

[tex]2L+S=36[/tex]

[tex]L-S=5.25[/tex]

We are asked for the price of small pizza, so we must manipulate the equations in such a way that adding or subtracting them removes the variable L and we are left with an equation for S.

Multiply the second equation of the system by -2

[tex](-2)(L-S=5.25)\\\\-2L+2S=-10.5[/tex]

and now we sum this with the first equation of the system:

[tex]-2L+2S=-10.5\\+(2L+S=36)\\-------------\\-2L+2L+2S+S=-10.5+36[/tex]

simplifying the result:

[tex]3S=25.5[/tex]

and solving for S (the price of a small pizza)

[tex]S=25.5/3\\S=8.5[/tex]

Answer:

The answer is 2/7.

Step-by-step explanation:

You have to cut out the common terms :

[tex] \frac{20x}{70x} [/tex]

[tex] \frac{20}{70} [/tex]

[tex] \frac{2}{7} [/tex]

Answer:

[tex]\frac{12}{35}[/tex]

Step-by-step explanation:

[tex]\frac{-4}{5} * \frac{3}{5} * (\frac{-6}{7} ) * \frac{5}{6}[/tex]

[tex]\frac{(-4) * 3}{5 * 1} * \frac{(-1)}{7} \\\\\frac{12}{35}[/tex]

Answer:

The tank will contain 202 Ib of salt when it's full.

Step-by-step explanation

To find the amount of salt in the tank at time t= x(t)

If x(0)= 90Ib

To find the volume of the tank at time t

V(t)= 90+(4-3)t=90+t gal

Other solutions are found attached

Answer:

-1.

Step-by-step explanation:

The standard form of a line can be written y = mx + b where m is the slope.

y = x + 5 can be written as y = 1x + 5 which shows that the slope is 1.

If the slope of a line  is m then the slope of a line perpendicular to it is -1/m.

So the required slope is -1/1 = -1.

Answer:

-1

Step-by-step explanation:

the line is exactly opposite like a mirror image when it is perpendicular,

so the gradient of the first line is 1 (because there is no number beside x, the gradient would be 1), that means the opposite of 1 would be -1.

The answer is -1

Answer:

£135 is the correct answer.

Step-by-step explanation:

Let C be the cost of table.

And let R be the radius of table.

Cost of table is directly proportional to square of radius.

As per question statement:

[tex]C\propto R^{2}[/tex] or

[tex]C=a\times R^2 ....... (1)[/tex]

where [tex]a[/tex] is the constant to remove the [tex]\propto sign[/tex].

It is given that

[tex]C_1 =[/tex] £60 and [tex]R_1 = 50\ cm[/tex]

[tex]C_2 = ?[/tex] when [tex]R_2= 75\ cm[/tex]

Putting the values of [tex]C_1[/tex] and [tex]R_1[/tex] in equation (1):

[tex]60=a \times 50^2 ....... (2)[/tex]

Putting the values of [tex]C_2[/tex] and [tex]R_2[/tex] in equation (1):

[tex]C_2=a \times 75^2 ....... (3)[/tex]

Dividing equation (2) by (3):

[tex]\dfrac{60}{C_2}= \dfrac{a \times 50^2}{a \times 75^2}\\\Rightarrow \dfrac{60}{C_2}= \dfrac{50^2}{75^2}\\\Rightarrow \dfrac{60}{C_2}= \dfrac{2^2}{3^2}\\\Rightarrow \dfrac{60}{C_2}= \dfrac{4}{9}\\\Rightarrow C_2 = 15 \times 9 \\\Rightarrow C_2 = 135[/tex]

So, £135 is the correct answer.

Answer:

[tex]\dfrac{y^2}{225} -\dfrac{x^2}{216}=1[/tex]

Step-by-step explanation:

For a hyperbolic mirror the two foci are 42 cm apart.

The distance between the foci = 2c.

Therefore:

The distance of the vertex from one focus = 6 cm

The distance of the vertex from the other focus = 36 cm

2a=36-6=30

Now:

[tex]c^2=a^2+b^2\\21^2=15^2+b^2\\b^2=21^2-15^2\\b^2=216\\b=6\sqrt{6}[/tex]

If the transverse axis lies on the y-axis, and the hyperbola is centered at the origin. Then the hyperbola has an equation of the form:

[tex]\dfrac{y^2}{a^2} -\dfrac{x^2}{b^2}=1[/tex]

Therefore, the equation of the hyperbola is:

[tex]\dfrac{y^2}{225} -\dfrac{x^2}{216}=1[/tex]

Complete Question

From the mid-1960's to the early 1990's, there was a slow but steady decline in SAT scores. For example, take the Verbal SAT. The average in 1967 was about 543; by 1994, the average was down to about 499. However, the SD stayed close to 110. The drop in average has a large effect on the tails of the distribution.

Estimate the percentage of students scoring over 700 on 1967.

A 0.7%

B  7%

C 7.67%

D 7.6%

Answer:

The correct option is D

Step-by-step explanation:

From the question we are told that

   The average  SAT score in 1967 is  [tex]\= x_1 =543[/tex]

     The  standard deviation of score in 1967 is  [tex]\sigma_ 1= 110[/tex]

     The average  SAT score in 1994 is  [tex]\= x_2 = 499[/tex]

      The  standard deviation of score in 1967 is  [tex]\sigma_ 2 = 110[/tex]

The percentage of students scoring over 700 on 1967 is mathematically represented as

   [tex]P(X > 700)[/tex]

Where X is the random variable representing score of student above 700

Now  normalizing the above probability we have

     [tex]P(X > 700) = P(Z > \frac{700 - \= x_1 }{\sigma } )[/tex]

substituting values

      [tex]= P(Z > \frac{700 - \= 543}{110 } )[/tex]

      [tex]= P(Z > 1.83 )[/tex]

Form the normalized z table  

      =  0.076

     =  7.6 %