How do you know the correct order in which to evaluate algebraic expressions?

I REALLYY NEED HELPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPP

Anna35 [415]

Answer:

12

Step-by-step explanation:

72/2 is 36

72/6 is 12

36 is a factor of 12

therefore 12 is the answer

8 0

3 years ago

Read 2 more answers

The Arizona Department of Transportation wishes to survey state residents to determine what proportion of the population would l

skad [1K]

Answer:

They need to survey 4145 residents.

Step-by-step explanation:

In a sample with a number n of people surveyed with a probability of a success of $\pi$ , and a confidence level of $1-\alpha$ , we have the following confidence interval of proportions.

$\pi \pm z\sqrt{\frac{\pi(1-\pi)}{n}}$

In which

z is the z-score that has a p-value of $1 - \frac{\alpha}{2}$ .

The margin of error is given by:

$M = z\sqrt{\frac{\pi(1-\pi)}{n}}$

99% confidence level

So $\alpha = 0.01$ , z is the value of Z that has a p-value of $1 - \frac{0.01}{2} = 0.995$ , so $Z = 2.575$ .

At least how many residents do they need to survey if they want to be at least 99% confident that the sample proportion is within 0.02 of the true proportion?

This is n for which $M = 0.02$ . As we have no estimate for the proportion, we use $\pi = 0.5$ . So

$M = z\sqrt{\frac{\pi(1-\pi)}{n}}$

$0.02 = 2.575\sqrt{\frac{0.5*0.5}{n}}$

$0.02\sqrt{n} = 2.575*0.5$

$\sqrt{n} = \frac{2.575*0.5}{0.02}$

$(\sqrt{n})^2 = (\frac{2.575*0.5}{0.02})^2$

$n = 4144.1$

Rounding up:

They need to survey 4145 residents.

4 0

3 years ago

The slope of the rafter is 15 m.Half the run of the rafter measure 12m.find the height of the ridge from the base

Korvikt [17]

Answer:

$9\; \rm m$ .

Step-by-step explanation:

Assume that the run of this rafter is level. Then the height of the ridge (the line with a question mark next to it in the diagram) should be perpendicular to the line marked with $\rm 12\; m$ . The three labelled lines in this diagram will form a right triangle.

The line marked as $15\; \rm m$ will be the hypotenuse of this right triangle.
The line marked as $12\; \rm m$ will be one of the triangle's legs.
The line representing the height of the ridge (the one with the question mark) will be the other leg of this right triangle.

Hence, the height of this ridge can be found with the Pythagorean Theorem. By the Pythagorean Theorem:

$(\text{First Leg})^2 + (\text{Second Leg})^2 = (\text{Hypotenuse})^2$ .

In this particular right triangle:

$(\text{Height})^2 + (12\; \rm m)^2 = (15\; \rm m)^2$ .

$(\text{Height})^2 = (15\; \rm m)^2 - (12\; \rm m)^2$ .

Therefore, the height of this ridge would be $\sqrt{81}\; \rm m = 9\; \rm m$ . (Note the unit.)

4 0

3 years ago

The figure below shows a shaded rectangular region inside a large rectangle:

Westkost [7]

The answer to your question is 64.

7 0

3 years ago

Consider the linear equation, 2.5n + 5.2 = 35.2.

OverLord2011 [107]

Answer:

Subtraction Property of Equality

Step-by-step explanation:

When solving an equation for a variable (in this case n), we want to move all of the n-terms to 1 side and the non-n terms to the other side. To do this, we can subtract 5.2 from both sides to leave 2.5n by itself. The property we used to do this is the Subtraction Property of Equality which states that if you subtract a quantity from one side of an equation, you must also subtract that same quantity from the other side of the equation.

5 0

4 years ago