How do you find the ratio of 42 girls to 63 boys?

A fence must be built to enclose a rectangular area of 20,000 ftsquared. fencing material costs $ 1 per foot for the two sides f

Simora [160]

The total cost of the least expensive fence would be $800.

To minimize perimeter and maximize area we take factors that are as close to equal as possible. In this case, the closest whole number factors are 200 and 100. Since the north and south faces cost less, we will make those 100 ft and make the more expensive east and west faces 200 ft.

100 ft × $2/ft = $200 per side × 2 sides = $400 for the north and south facing sides.

200 ft × $1/ft = $200 per side × 2 sides = $400 for the east and west facing sides

$400 + $400 = $800

6 0

3 years ago

Find the area of a circle with a circumfrence of 53.41 inches

netineya [11]

About 224.7 I think. I hope this helps

7 0

3 years ago

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If the coefficient of correlation is a positive value, then the slope of the regression line

ratelena [41]

Answer:

must also be positive

Step-by-step explanation:

The sign of the correlation coefficient indicates whether the fitted line is sloping upwards or downwards, so it should be consistent with the sign of the slope of the fitted line. so if the correlation line is poitive so should the regression line

6 0

3 years ago

Rabies is an often-fatal disease typically transmitted through the bite of an infected animal. The state of Florida has been rec

slega [8]

Answer:

a) 3.6

b) 1.897

c)0.0273

d) 0.9727

Step-by-step explanation:

Rabies has a rare occurrence and we can assume that events are independent. So, X the count of rabies cases reported in a given week is a Poisson random variable with μ=3.6.

a)

The mean of a Poisson random variable X is μ.

mean=E(X)=μ=3.6.

b)

The standard deviation of a Poisson random variable X is √μ.

standard deviation=S.D(X)=√μ=√3.6=1.897.

c)

The probability for Poisson random variable X can be calculated as

P(X=x)=(e^-μ)(μ^x)/x!

where x=0,1,2,3,...

So,

P(no case of rabies)=P(X=0)=e^-3.6(3.6^0)/0!

P(no case of rabies)=P(X=0)=0.0273.

d)

P(at least one case of rabies)=P(X≥1)=1-P(X<1)=1-P(X=0)

P(at least one case of rabies)=1-0.0273=0.9727

8 0

3 years ago

How to work vector algebra

erica [24]

Vectors and vector addition:

A scalar is a quantity like mass or temperature that only has a magnitude. On the other had, a vector is a mathematical object that has magnitude and direction. A line of given length and pointing along a given direction, such as an arrow, is the typical representation of a vector. Typical notation to designate a vector is a boldfaced character, a character with and arrow on it, or a character with a line under it (i.e., ). The magnitude of a vector is its length and is normally denoted by or A. Addition of two vectors is accomplished by laying the vectors head to tail in sequence to create a triangle such as is shown in the figure. The following rules apply in vector algebra.where P and Q are vectors and a is a scalar.

Unit vectors:

A unit vector is a vector of unit length. A unit vector is sometimes denoted by replacing the arrow on a vector with a "^" or just adding a "^" on a boldfaced character (i.e., ). Therefore, Any vector can be made into a unit vector by dividing it by its length. Any vector can be fully represented by providing its magnitude and a unit vector along its direction.

Base vectors and vector components:

Base vectors are a set of vectors selected as a base to represent all other vectors. The idea is to construct each vector from the addition of vectors along the base directions. For example, the vector in the figure can be written as the sum of the three vectors u1, u2, and u3, each along the direction of one of the base vectors e1, e2, and e3, so that Each one of the vectors u1, u2, and u3 is parallel to one of the base vectors and can be written as scalar multiple of that base. Let u1, u2, and u3 denote these scalar multipliers such that one has The original vector u can now be written as The scalar multipliers u1, u2, and u3 are known as the components of u in the base described by the base vectors e1, e2, and e3. If the base vectors are unit vectors, then the components represent the lengths, respectively, of the three vectors u1, u2, and u3. If the base vectors are unit vectors and are mutually orthogonal, then the base is known as an orthonormal, Euclidean, or Cartesian base.

A vector can be resolved along any two directions in a plane containing it. The figure shows how the parallelogram rule is used to construct vectors a and b that add up to c. In three dimensions, a vector can be resolved along any three non-coplanar lines. The figure shows how a vector can be resolved along the three directions by first finding a vector in the plane of two of the directions and then resolving this new vector along the two directions in the plane. When vectors are represented in terms of base vectors and components, addition of two vectors results in the addition of the components of the vectors.

8 0

3 years ago

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