All categories

3 years ago

PLEASE HELP WITH 12A!!!!10 POINTS!!!!

Mathematics

2 answers:

Andreyy893 years ago

8 0

A. 219 fsquared

B. 220 ftsquared

enyata [817]3 years ago

3 0

219.3 ft^2

rounded to the nearest ft^2

look at the tenth place which is 3 (less that 5 so it stays the same)

219 ft^2

rounded to the nearest 10 ft^2

look at the ones place 9 ( 5 and above round up)

220 ft^2

You might be interested in

9( 2k + 3 ) + 2 = 11 ( k- y )

Mashcka [7]

9(2k+3)+2=11 (k-y)
k=-11/7 y+ -29/7

8 0

3 years ago

Read 2 more answers

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

2 years ago

3643 in scientific notation

Lesechka [4]

3.643 x 10^3
move the decimal in between the first and second number
However many times you move the decimal, that is you exponent.

6 0

3 years ago

Is 3/20 larger then 2

aleksley [76]

To find out is 3/20 is larger than 2 we will convert 3/20 to a decimal. Lets do it:-

3/20
3 ÷ 20 = 0.15

Is 0.15 larger than 2?

No, 0.15 is not larger than 2.

So, 3/20 isn't larger than 2.

Hope I helped ya!! xD

8 0

3 years ago

Read 2 more answers

Its pretty easy if you are good at math! Please help!

aleksley [76]

Step-by-step explanation:

Explanation:

The trick is to know about the basic idea of sequences and series and also knowing how i cycles.

The powers of i will result in either: i, −1, −i, or 1.

We can regroup i+i2+i3+⋯+i258+i259 into these categories.

We know that i=i5=i9 and so on. The same goes for the other powers of i.

So:

i+i2+i3+⋯+i258+i259

=(i+i5+⋯+i257)+(i2+i6+⋯+i258)+(i3+i7+⋯+i259)+(i4+i8+⋯+i256)

We know that within each of these groups, every term is the same, so we are just counting how much of these are repeating.

=65(i)+65(i2)+65(i3)+64(i4)

From here on out, it's pretty simple. You just evaluate the expression:

=65(i)+65(−1)+65(−i)+64(1)

=65i−65−65i+64

=−65+64

=−1

So,

i+i2+i3+⋯+i258+i259=-1

8 0

3 years ago