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3 years ago

Doris is investigating if height has any effect on red blood cell count. What is the explanatory variable?

Mathematics

1 answer:

sammy [17]3 years ago

5 0

Answer:

a) The number of people that are being studied.

Step-by-step explanation:

1) The (missing) options are:

a) The number of people that are being studied.

b) red blood cell count

c) height

d) none of the above

2) Explanatory variables are synonymical terms for independent variables.

In short when those variables are really not affected by other ones they are also called Explanatory Variables.

It is useful to make a distinction between response variable, and explanatory ones. The first one is affected somehow and it is the response Doris wants to find out.

3) Certainly, the sample or population of this research is absolutely free of prior influence over the final results. Since theoretically, the same research can be done over different samples and find other responses.

Then it's "a"

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Please solve a and b! Thanks.

Dvinal [7]

B.225/20 =11.25 prr hour
a.225/20=h

7 0

3 years ago

What is the value of the tangent of

kiruha [24]

Answer:

Step-by-step explanation:

With reference < H

perpendicular (p) = 12

base (b) = 5

so now

tangent of < H

= p / b

= 12 / 5

hope it helps :)

7 0

3 years ago

Read 2 more answers

When calculating accrued interest over several years that compounds annually, you must _____.

Darina [25.2K]

When calculating accrued interest over several years that compounds annually, you must calculate a new principle each year, adding the accrued interest from the previous year. At the beginning of the new interest period, all the accrued interest is added to the principal which forms a new principle figure that the interest is then counted on.

3 0

3 years ago

A hiker starting at point P on a straight road wants to reach a forest cabin that is 2 km from a point Q, 3 km down the road fro

pantera1 [17]

Answer:

2.19 km

Step-by-step explanation:

If x is the distance she walks down the road before turning, then the total time is:

t = x/8 + √((3 − x)² + 2²) / 3

t = x/8 + √(9 − 6x + x² + 4) / 3

24t = 3x + 8√(13 − 6x + x²)

24t = 3x + 8(13 − 6x + x²)^½

Take derivative of both sides with respect to x.

24 dt/dx = 3 + 4(13 − 6x + x²)^-½ (-6 + 2x)

When t is a minimum, dt/dx = 0.

0 = 3 + 4(13 − 6x + x²)^-½ (-6 + 2x)

-3 = 4(13 − 6x + x²)^-½ (-6 + 2x)

3 / (6 − 2x) = 4(13 − 6x + x²)^-½

3 / (24 − 8x) = (13 − 6x + x²)^-½

(24 − 8x) / 3 = (13 − 6x + x²)^½

(24 − 8x)² / 9 = 13 − 6x + x²

576 − 384x + 64x² = 117 − 54x + 9x²

459 − 330x + 55x² = 0

Solve with quadratic formula.

x = [ 330 ± √((-330)² − 4(55)(459)) ] / 2(55)

x = (330 ± √7920) / 110

x = 2.19 or 3.81

Since 0 < x < 3, x = 2.19.

7 0

3 years ago

Why does a radical function with an even index only appear on one sode of the x-axis while a radical woth an odd index appears o

Vladimir79 [104]

Consider the equation y = x^2. No matter what x happens to be, the result y will never be negative even if x is negative. Example: x = -3 leads to y = x^2 = (-3)^2 = 9 which is positive.

Since y is never negative, this means the inverse x = sqrt(y) has the right hand side never be negative. The entire curve of sqrt(x) is above the x axis except for the x intercept of course. Put another way, we cannot plug in a negative input into the square root function for this reason. This similar idea applies to any even index such as fourth roots or sixth roots.

Meanwhile, odd roots such as a cube root has its range extend from negative infinity to positive infinity. Why? Because y = x^3 can have a negative output. Going back to x = -3 we get y = x^3 = (-3)^3 = -27. So we can plug a negative value into the cube root to get some negative output. We can get any output we want, negative or positive. So the range of any radical with an odd index is effectively the set of all real numbers. Visually this produces graphs that have parts on both sides of the x axis.

3 0

3 years ago