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3 years ago

Which biconditional is not a good definition?

1 answer:

4 0

The correct answers are:

A ray is a bisector of an angle if and only if it splits the angle into two angles; and
A) I can afford to buy a ticket.

Explanation:

For the first question, the first three answers are very specific and true:

A whole number is odd if it is not divisible by 2, and a number is not divisible by 2 if it is odd;
an angle is straight if its measure is 180 degrees, and the measure of an angle is 180 degrees if it is a straight angle;
a whole number is even if it is divisible by 2, and a number is divisible by 2 if it is even.

However, with the fourth choice, we are missing a key word in the definition. A ray is a bisector of an angle if and only if it splits the angle into two CONGRUENT angles. It is not just a ray that cuts an angle into two pieces, the pieces must be equal.

For the second question, the Law of Detachment says if our conditional "if p, then q" is true and p is true, then q must also be true.

For this question, "I can go to the concert if I can afford to buy a ticket" is true as well as "I can go to the concert." This means "I can afford to buy a ticket" must be true as well.

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Troy drove 14 miles east and then 8 miles north. How far is

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The answer is 6 and that’s after it’s rounded

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3 years ago

Rachel multiplied each side of x ≥ 2 by 3. She wrote the result as 3x ≤ 6. Explain the error Rachel made.

andrey2020 [161]

Answer:

Her mistake was to change the inequality sign from ≥ to ≤.

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2 years ago

37.5% 1/3 25% and 3/10 least to greatest

barxatty [35]

25% 3/10 1/3 and 37.5%

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3 years ago

Round the following percentages to one decimal place.0.698%53.123%0.075%34.337%3.876%

balandron [24]

To round off a given number in decimals to one decimal place (1 dp), we simply take the figure right after the decimal and approximate the remaining after it. If the second number after the decimal is a significant number (5 and above) we make it 1 and add to the number right after the decimal. If its NOT a significant number, we simply disregard it. The solutions therefore are;

ANSWER:

$\begin{gathered} \text{Rounded to one decimal place;} \\ (1)0.698\%\approx0.7 \\ (2)53.123\%\approx53.1 \\ (3)0.075\%\approx0.1 \end{gathered}$

Notice how the number in (1) becomes 0.7, after taking the next number (which is 9) and adding it as 1 to the number after the decimal (which is 6). The same applies to the number in (3).

$\begin{gathered} (4)34.337\%\approx34.3 \\ (5)3.876\%\approx3.9 \end{gathered}$

4 0

1 year ago

For a certain river, suppose the drought length Y is the number of consecutive time intervals in which the water supply remains

AnnZ [28]

Answer:

a) There is a 9% probability that a drought lasts exactly 3 intervals.

There is an 85.5% probability that a drought lasts at most 3 intervals.

b)There is a 14.5% probability that the length of a drought exceeds its mean value by at least one standard deviation

Step-by-step explanation:

The geometric distribution is the number of failures expected before you get a success in a series of Bernoulli trials.

It has the following probability density formula:

$f(x) = (1-p)^{x}p$

In which p is the probability of a success.

The mean of the geometric distribution is given by the following formula:

$\mu = \frac{1-p}{p}$

The standard deviation of the geometric distribution is given by the following formula:

$\sigma = \sqrt{\frac{1-p}{p^{2}}$

In this problem, we have that:

$p = 0.383$

$\mu = \frac{1-p}{p} = \frac{1-0.383}{0.383} = 1.61$

$\sigma = \sqrt{\frac{1-p}{p^{2}}} = \sqrt{\frac{1-0.383}{(0.383)^{2}}} = 2.05$

(a) What is the probability that a drought lasts exactly 3 intervals?

This is $f(3)$

$f(x) = (1-p)^{x}p$

$f(3) = (1-0.383)^{3}*(0.383)$

$f(3) = 0.09$

There is a 9% probability that a drought lasts exactly 3 intervals.

At most 3 intervals?

This is $P = f(0) + f(1) + f(2) + f(3)$

$f(x) = (1-p)^{x}p$

$f(0) = (1-0.383)^{0}*(0.383) = 0.383$

$f(1) = (1-0.383)^{1}*(0.383) = 0.236$

$f(2) = (1-0.383)^{2}*(0.383) = 0.146$

Previously in this exercise, we found that $f(3) = 0.09$

$P = f(0) + f(1) + f(2) + f(3) = 0.383 + 0.236 + 0.146 + 0.09 = 0.855$

There is an 85.5% probability that a drought lasts at most 3 intervals.

(b) What is the probability that the length of a drought exceeds its mean value by at least one standard deviation?

This is $P(X \geq \mu+\sigma) = P(X \geq 1.61 + 2.05) = P(X \geq 3.66) = P(X \geq 4)$ .

We are working with discrete data, so 3.66 is rounded up to 4.

Either a drought lasts at least four months, or it lasts at most thee. In a), we found that the probability that it lasts at most 3 months is 0.855. The sum of these probabilities is decimal 1. So:

$P(X \leq 3) + P(X \geq 4) = 1$

$0.855 + P(X \geq 4) = 1$

$P(X \geq 4) = 0.145$

There is a 14.5% probability that the length of a drought exceeds its mean value by at least one standard deviation

8 0

3 years ago