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3 years ago

^^^!!! 25 pOinTs (seriously help)

Mathematics

1 answer:

bonufazy [111]3 years ago

7 0

Answer:

A) Θ = 2A/r²

Step-by-step explanation:

A = Θr²/2

(Multiple both sides by 2)

2A = Θr²

(Divide both sides by r²)

2A/r² = Θ

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Katlyn made 4 dresses with 7 yards of fabric. How many yards did she us on 1 dress?

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Kaitlyn will use 1.75 yard of fabric

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Multiply (x+3)(x-4) what is the middle term in the simplified product? x -x 3x -4x

Nesterboy [21]

Answer:

The answer is -x

Step-by-step explanation:

(x+3)(x-4)

x²-4x+3x-12

x²-x-12

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According to the Behavioral Risk Factor Surveillance System, 58% of all Americans adhere to a sedentary lifestyle (sedentary mea

sammy [17]

Answer:

Step-by-step explanation:

Hello!

The variable is X: number of sedentary people in a sample of 12.

This is a discrete variable with a binomial distribution and the probability of success is p=0.58. To determine if a variable has or not a binomial distribution you have to see if it follows the binomial criteria:

Binomial criteria:

1. The number of observation of the trial is fixed n=12

2. Each observation in the trial is independent, this means that none of the trials will affect the probability of the next trial. The activity habits on each person are independent of the others.

3. The probability of success in the same from one trial to another p=0.58

So X≈ Bi (n;ρ)

a. If you were to take a sample of n=12.

The expected value (mean) is E(X)= n*p= 0.58*12= 6.96

And the Standard deviation:

V(X)= n*p*q= 12*0.58*(1-0.58)= 2.92

√V(X)= 1.71

b. I'll calculate the probability of exactly 10 persons having sedentary habits using the table of cumulative probabilities, to do so, you have to look for the accumulated probability until 10 and subtract the accumulative probability until 9:

P(X=10) = P(X≤10) - P(X≤9)= 0.9859 - 0.9358= 0.050

I hope you have a SUPER day!

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4 years ago

Find the area of the parallelogram.

Anit [1.1K]

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Step-by-step explanation:

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Suppose the weights of tight ends in a football league are normally distributed such that σ2=400. A sample of 11 tight ends was

AlladinOne [14]

Answer:

$217.636-1.96\frac{20}{\sqrt{11}}=205.817$

$217.636+1.96\frac{20}{\sqrt{11}}=229.455$

So on this case the 95% confidence interval would be given by (205.82;229.46)

Step-by-step explanation:

Assuming the following data: Weight 150 169 170 196 200 218 219 262 269 270 271

Previous concepts

A confidence interval is "a range of values that’s likely to include a population value with a certain degree of confidence. It is often expressed a % whereby a population means lies between an upper and lower interval".

The margin of error is the range of values below and above the sample statistic in a confidence interval.

Normal distribution, is a "probability distribution that is symmetric about the mean, showing that data near the mean are more frequent in occurrence than data far from the mean".

$\bar X$ represent the sample mean for the sample

$\mu$ population mean (variable of interest)

$\sigma= \sqrt{400}= 20$ represent the population standard deviation

n=11 represent the sample size

Solution to the problem

The confidence interval for the mean is given by the following formula:

$\bar X \pm z_{\alpha/2}\frac{\sigma}{\sqrt{n}}$ (1)

In order to calculate the mean we can use the following formula:

$\bar X= \sum_{i=1}^n \frac{x_i}{n}$ (2)

The mean calculated for this case is $\bar X=217.636$

Since the Confidence is 0.95 or 95%, the value of $\alpha=0.05$ and $\alpha/2 =0.025$ , and we can use excel, a calculator or a table to find the critical value. The excel command would be: "=NORM.INV(0.025,0,1)".And we see that $z_{\alpha/2}=1.96$

Now we have everything in order to replace into formula (1):

$217.636-1.96\frac{20}{\sqrt{11}}=205.817$

$217.636+1.96\frac{20}{\sqrt{11}}=229.455$

So on this case the 95% confidence interval would be given by (205.82;229.46)

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4 years ago