PLEASE HELP WITH QUESTIONS 4 AND 5

The sum of two consecutive integers is 7,903. What are the integers.

dimaraw [331]

The answer for the first question would be 3952+3952 =7903

5 0

3 years ago

Some types of algae have the potential to cause damage to river ecosystems. Suppose the accompanying data on algae colony densit

Phantasy [73]

Answer:

$y=-2.95836 x +234.56159$

Step-by-step explanation:

We assume that th data is this one:

x: 50, 55, 50, 79, 44, 37, 70, 45, 49

y: 152, 48, 22, 35, 43, 171, 13, 185, 25

a) Compute the equation of the least-squares regression line. (Round your numerical values to five decimal places.)For this case we need to calculate the slope with the following formula:

$m=\frac{S_{xy}}{S_{xx}}$

Where:

$S_{xy}=\sum_{i=1}^n x_i y_i -\frac{(\sum_{i=1}^n x_i)(\sum_{i=1}^n y_i)}{n}$

$S_{xx}=\sum_{i=1}^n x^2_i -\frac{(\sum_{i=1}^n x_i)^2}{n}$

So we can find the sums like this:

$\sum_{i=1}^n x_i =50+ 55+ 50+ 79+ 44+ 37+ 70+ 45+ 49=479$

$\sum_{i=1}^n y_i =152+ 48+ 22+ 35+ 43+ 171+ 13+ 185+ 25=694$

$\sum_{i=1}^n x^2_i =50^2 + 55^2 + 50^2 + 79^2 + 44^2 + 37^2 + 70^2 + 45^2 + 49^2=26897$

$\sum_{i=1}^n y^2_i =152^2 + 48^2 + 22^2 + 35^2 + 43^2 + 171^2 + 13^2 + 185^2 + 25^2=93226$

$\sum_{i=1}^n x_i y_i =50*152+ 55*48+ 50*22+ 79*35+ 44*43+ 37*171+ 70*13+ 45*185+ 49*25=32784$

With these we can find the sums:

$S_{xx}=\sum_{i=1}^n x^2_i -\frac{(\sum_{i=1}^n x_i)^2}{n}=26897-\frac{479^2}{9}=1403.556$

$S_{xy}=\sum_{i=1}^n x_i y_i -\frac{(\sum_{i=1}^n x_i)(\sum_{i=1}^n y_i)}=32784-\frac{479*694}{9}=-4152.22$

And the slope would be:

$m=-\frac{-4152.222}{1403.556}=-2.95836$

Nowe we can find the means for x and y like this:

$\bar x= \frac{\sum x_i}{n}=\frac{479}{9}=53.222$

$\bar y= \frac{\sum y_i}{n}=\frac{694}{9}=77.111$

And we can find the intercept using this:

$b=\bar y -m \bar x=77.1111111-(-2.95836*53.22222222)=234.56159$

So the line would be given by:

$y=-2.95836 x +234.56159$

7 0

3 years ago

Solve the initial value problem. 7y′−4y=e−πt2, y(0)=a Let a0 be the value of a for which the transition from one type of long-ru

densk [106]

Answer:

as shown in the attached file

Step-by-step explanation:

The detailed steps and application of differential equation, the use of integrating factor to generate the solution and to solve for the initial value problem is as shown in the attached file.

8 0

3 years ago

A square field has a perimeter of 44 meters.Find the length of one side of the field

riadik2000 [5.3K]

11 Meters because squares have 4 even sides. So you divide 44 by 4 and you get 11. This means every side is 11 meters long.

6 0

3 years ago

List P contains m numbers; list Q contains n numbers. If the two lists are combined to produce list R, containing m + n numbers,

Anarel [89]

Answer: YES

Step-by-step explanation:

We need to write out the expressions

P= {m}

Q= {n}

R= {m+n}

If 2m=n then we can say;

P= {½n} Q= {n} & R= {³/²n}

It is obvious that the smaller number in Q is greater than the largest number in P

We can make some assumptions.

Let n= (x,y,z)

Consequently,

P={½x,½y,½z} Q={x,y,z} and R= {1.5x,1.5y,1.5z}

Therefore the median will be the middle element,

Median of P= ½y

Median of Q = y

Median of R = 1.5y

And 1.5y>1.5y

Then we can agree that the median of R is greater than the median of both P and Q

5 0

4 years ago