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3 years ago

Recite the mnemonic that we can use to help remember the ratios for sine, cosine,and tangent?What does each piece stand for?

Mathematics

1 answer:

Effectus [21]3 years ago

7 0

SOHCAHTOA

Sine
obtuse over horizontal
Cosine
Acute over Horizontal
Tangent
Obtuse over acute

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Can I please get some help

Aleksandr [31]

Answer:

a. $1.76$

b. $2.5$

Step-by-step explanation:

You have the following formula given in the exercise:

$t=\frac{\sqrt{100-h}}{4}$

a. If the object is 50 feet above the ground, you can identify that the value of the variable "h" would be the following:

$h=50$

Then, knowing that value, you can substitute it into the given formula and then evaluate in order to calculate the time in seconds for the object to be 50 feet above the ground.

This is:

$t=\frac{\sqrt{100-50}}{4}\\\\t=1.76$

b. When the object reaches the ground, the value of "h" is:

$h=0$

Therefore, substituting this value into the formula and evaluating, you get that time (in seconds) it takes to the object reaches the ground is:

$t=\frac{\sqrt{100-0}}{4}\\\\t=2.5$

7 0

2 years ago

Of the population of all fruit flies we wish to give a 90% confidence interval for the fraction which possess a gene which gives

Eva8 [605]

Answer:

The margin of error for the 90% confidence interval is of 0.038.

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 zscore that has a pvalue of $1 - \frac{\alpha}{2}$ .

The margin of error is of:

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

To this end we have obtained a random sample of 400 fruit flies. We find that 280 of the flies in the sample possess the gene.

This means that $n = 400, \pi = \frac{280}{400} = 0.7$

90% confidence level

So $\alpha = 0.1$ , z is the value of Z that has a pvalue of $1 - \frac{0.1}{2} = 0.95$ , so $Z = 1.645$ .

Margin of error:

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

$M = 1.645\sqrt{\frac{0.7*0.3}{400}}$

$M = 0.038$

The margin of error for the 90% confidence interval is of 0.038.

8 0

2 years ago

Based on past experience, the main printer in a university computer centre is operating properly 90% of the time. Suppose inspec

yaroslaw [1]

Answer:

a) 38.74% probability that the main printer is operating properly for exactly 9 inspections.

b) Approximately 100% probability that the main printer is operating properly for at least 3 inspections.

c) The expected number of inspections in which the main printer is operating properly is 9.

Step-by-step explanation:

For each inspection, there are only two possible outcomes. Either it is operating correctly, or it is not. The probability of the printer operating correctly for an inspection is independent of any other inspection, which means that the binomial probability distribution is used to solve this question.

Binomial probability distribution

The binomial probability is the probability of exactly x successes on n repeated trials, and X can only have two outcomes.

$P(X = x) = C_{n,x}.p^{x}.(1-p)^{n-x}$

In which $C_{n,x}$ is the number of different combinations of x objects from a set of n elements, given by the following formula.

$C_{n,x} = \frac{n!}{x!(n-x)!}$

And p is the probability of X happening.

Based on past experience, the main printer in a university computer centre is operating properly 90% of the time.

This means that $p = 0.9$

Suppose inspections are made at 10 randomly selected times.

This means that $n = 10$

A) What is the probability that the main printer is operating properly for exactly 9 inspections.

This is $P(X = 9)$ . So

$P(X = x) = C_{n,x}.p^{x}.(1-p)^{n-x}$

$P(X = 9) = C_{10,9}.(0.9)^{9}.(0.1)^{1} = 0.3874$

38.74% probability that the main printer is operating properly for exactly 9 inspections.

B) What is the probability that the main printer is operating properly for at least 3 inspections?

This is:

$P(X \geq 3) = 1 - P(X < 3)$

In which

$P(X < 3) = P(X = 0) + P(X = 1) + P(X = 2)$

$P(X = x) = C_{n,x}.p^{x}.(1-p)^{n-x}$

$P(X = 0) = C_{10,0}.(0.9)^{0}.(0.1)^{10} \approx 0$

$P(X = 1) = C_{10,1}.(0.9)^{1}.(0.1)^{9} \approx 0$

$P(X = 2) = C_{10,2}.(0.9)^{2}.(0.1)^{8} \approx 0$

Thus:

$P(X < 3) = P(X = 0) + P(X = 1) + P(X = 2) = 0 + 0 + 0 = 0$

Then:

$P(X \geq 3) = 1 - P(X < 3) = 1 - 0 = 1$

Approximately 100% probability that the main printer is operating properly for at least 3 inspections.

C) What is the expected number of inspections in which the main printer is operating properly?

The expected value for the binomial distribution is given by:

$E(X) = np$

In this question:

$E(X) = 10(0.9) = 9$

3 0

3 years ago

What's the midpoint of a line segment joining the points (5, –4) and (–13, 12)?

Vikki [24]

Answer:

The midpoint of the line segment is located at (-4, 4).

Step-by-step explanation:

We're given the coordinate points of a line that can help us find the midpoint.

The midpoint formula for a line is written as:

$\bullet \ \ \ \displaystyle\big(\frac{x_1+x_2}{2}, \frac{y_1+y_2}{2}\big)$

Additionally, we are given the coordinate points (5, -4) and (-13, 12). We can use these and label them with the (x, y) system so we can substitute them into the formula.

In math, a coordinate pair is written as (x, y). This is where cos = x and sin = y. If we are given two coordinate pairs, we can label them with the (x, y) system but also incorporating a subscript to distinguish the two x-values from each other as well as the y-values. We do this by turning the two x-values into x₁ and x₂ and the y-values follow the same protocol: y₁ and y₂.

Therefore, we can label our two coordinates:

x₁ = 5
y₁ = -4

x₂ = -13
y₂ = 12

Now, we can place these values into the midpoint formula and simplify to find our midpoint.

Recall that the midpoint formula is:

$\bullet \ \ \ \displaystyle\big(\frac{x_1+x_2}{2}, \frac{y_1+y_2}{2}\big)$

Therefore, let's substitute these values.

$\displaystyle\big(\frac{x_1+x_2}{2}, \frac{y_1+y_2}{2}\big)\\\\\\\big(\frac{5 + (-13)}{2}, \frac{(-4)+12}{2}\big)\\\\\\\big(\frac{-8}{2}, \frac{8}{2}\big)\\\\\\\boxed{(-4, 4)}$

Therefore, the midpoint of the line segment is located at (-4, 4), which is Option A.

8 0

2 years ago

Read 2 more answers

A loaded pick-up truck travels 70 miles to deliver the load. For the trip back, the gas mileage is 20% better due to a lighter l

dexar [7]

Answer:

let me check the answer for you

3 0

2 years ago