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3 years ago

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The measure of angle t is 60 degrees. What is the x-coordinate of the point where the terminal side intersects the unit circle?

1 answer:

Anestetic [448]3 years ago

7 0

Angle t would be equal to cos(60 degrees) which has coordinates (1/2,sqrt3/2) so that answer is 1/2

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Nancy drove 400 miles in three days. She drove 113 on each of the first two days How many miles did she drive on the third day?

Gemiola [76]

113 what on each of the two day. Please clarify

4 0

3 years ago

Need answer asap. will give thanks

kompoz [17]

The answer of the larger circle = 254.34
Formula = radius*radius*π

The answer of the smaller circle = 113.04

254.34 - 113.04 = 141.3

Hope this helped☺☺

4 0

3 years ago

Read 2 more answers

Sequences and Series precalc multiple choice, will give brainliest.

Gala2k [10]

9514 1404 393

Answer:

False

Step-by-step explanation:

The given formula is the "explicit" formula for the sequence.

The recursive formula would be ...

a[1] = 160

a[n] = 1/2·a[n-1] . . . . each term expressed in as a function of previous terms

The given statement is false.

8 0

3 years ago

Mari and Jen each work 20 hours a week at different jobs. Mari earns twice as much as Jen. Together they earn $480. How much doe

Salsk061 [2.6K]

We will call:
M=Mari
J=Jen

Initial equations:

M=2J
M+J=480
(the fact that they work 20 hours a week is not needed in this problem information)

Plug in:
2J+J=480
3J=480
J=160

Jen makes $160 a week.

Therefore:

M=2J
M=2(160)
M=320

Mari makes $320 per week
Jen makes $160 per week

7 0

3 years ago

According to a Yale program on climate change communication survey, 71% of Americans think global warming is happening.† (a) For

SpyIntel [72]

Answer:

a) 0.2741 = 27.41% probability that at least 13 believe global warming is occurring

b) 0.7611 = 76.11% probability that at least 110 believe global warming is occurring

Step-by-step explanation:

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.

The expected value of the binomial distribution is:

$E(X) = np$

The standard deviation of the binomial distribution is:

$\sqrt{V(X)} = \sqrt{np(1-p)}$

Normal probability distribution

Problems of normally distributed samples can be solved using the z-score formula.

In a set with mean $\mu$ and standard deviation $\sigma$ , the zscore of a measure X is given by:

$Z = \frac{X - \mu}{\sigma}$

The Z-score measures how many standard deviations the measure is from the mean. After finding the Z-score, we look at the z-score table and find the p-value associated with this z-score. This p-value is the probability that the value of the measure is smaller than X, that is, the percentile of X. Subtracting 1 by the pvalue, we get the probability that the value of the measure is greater than X.

When we are approximating a binomial distribution to a normal one, we have that $\mu = E(X)$ , $\sigma = \sqrt{V(X)}$ .

In this problem, we have that:

$p = 0.71$

(a) For a sample of 16 Americans, what is the probability that at least 13 believe global warming is occurring?

Here $n = 16$ , we want $P(X \geq 13)$ . So

$P(X \geq 13) = P(X = 13) + P(X = 14) + P(X = 15) + P(X = 16)$

In which

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

$P(X = 13) = C_{16,13}.(0.71)^{13}.(0.29)^{3} = 0.1591$

$P(X = 14) = C_{16,14}.(0.71)^{14}.(0.29)^{2} = 0.0835$

$P(X = 15) = C_{16,15}.(0.71)^{15}.(0.29)^{1} = 0.0273$

$P(X = 16) = C_{16,16}.(0.71)^{16}.(0.29)^{0} = 0.0042$

$P(X \geq 13) = P(X = 13) + P(X = 14) + P(X = 15) + P(X = 16) = 0.1591 + 0.0835 + 0.0273 + 0.0042 = 0.2741$

0.2741 = 27.41% probability that at least 13 believe global warming is occurring

(b) For a sample of 160 Americans, what is the probability that at least 110 believe global warming is occurring?

Now $n = 160$ . So

$\mu = E(X) = np = 160*0.71 = 113.6$

$\sigma = \sqrt{V(X)} = \sqrt{np(1-p)} = \sqrt{160*0.71*0.29} = 5.74$

Using continuity correction, this is $P(X \geq 110 - 0.5) = P(X \geq 109.5)$ , which is 1 subtracted by the pvalue of Z when X = 109.5. So

$Z = \frac{X - \mu}{\sigma}$

$Z = \frac{109.5 - 113.6}{5.74}$

$Z = -0.71$

$Z = -0.71$ has a pvalue of 0.2389

1 - 0.2389 = 0.7611

0.7611 = 76.11% probability that at least 110 believe global warming is occurring

3 0

3 years ago