SK

This page lists questions and answers that were posted by visitors named SK.

Questions

The following questions were asked by visitors named SK.

How would you purify decanoic acid contaminated with biphenyl? what method and solvent.Please help me

What is “institutional discrimination?” Give an example

Having problems with less than/greater than decimals. Wanted to double check some answers. a)0.5_1.0 My Answer is < b)3.2_3.02 My answer > c)4.83_4.8 My answer < d)6.25_6.4 My answer < e)0.7_0.07 My Answer >

assume a pulley has a radius of 12.96 cm. If it takes 18 seconds for 56 cm of belt to go around the pulley, find the angular velocity in radians per seconds

A ship leaves its homeport and sails on a bearing of N28degrees10'E. Another ship leaves the same port at the same time and sails on a bearing of S61degrees50'E. If the first ship sails at 24.0 mph and second sails at 28mph, find the distance between the...

A plane flies 1.3 hr at 100mph on a bearing of N40degreesE. It then turns and flies 1.5hr at the same speed on a bearing of S50degreesE. How far is the plane from its starting point?

The angle of depression from the top of the building to a point on the ground is 29degrees30', the point of the ground is 36 meters from the top of the building. Find the height of the building

the angle of depression from the top of a building to a point on the ground is 32degrees30', how far is the point of the ground from the top of building if the building is 252m high?

find sin(s+t), given that sin t=1/3, t in quadrant 2, and cos s = -2/5, s in quadrant 3

Find the value of tangent of angle A, given cos2A = 4/5, and A terminates in quadrant 2

Use the double angle formula to verify the identity cotxsin2x=1+cos2x

What is the final pressure gas sample that is subjected to a temperature change from 22.0 C to 30.0 C and a volume change from 85.4 L to 37.0 L with an initial pressure 105 kPa?

I honestly can't figure out how to draw this structure and it's especially difficult for online homework. I've used up 2 tries and only have one more left! Can someone please help? Thank you so much! CH3C≡C(CH2)3C(CH3)3

An electrician charges a customer $260 for 4 hours. He charges one customer $150 for 2 hours. How much does he charge for his service fee, x, and his hourly charge, y, to his customers? Thank you!

What is the potential energy of an electron and proton in a hydrogen atom if the distance between them is 5.3*10^-11? ANSWER k=9*10^9 Q=1.6*10^-19 q=1.6*10^19 Ue=? Ue=KQq/r Ue=-4.4*10^-18 j

1. How does chronic stress affect the reproductive system women? 2. How might chronic stress affect the healing of a broken bone? 3. In your own words, how might you describe chronic stress? 4. Describe a chronic stressor in your life (past or present) or...

9. Write a paragraph about the asteroid theory of dinosaur extinction. Be sure to include any geological evidence.

What is the probability that X and -Y sum to a negative value?

For a given percentile range, what are the most ideal stock options to invest in for long-term growth?

What is the conditional probability P(Heads|X=1/4)?

Let X and Y be independent positive random variables. Let Z=X/Y . In what follows, all occurrences of x , y , z are assumed to be positive numbers. 1) Suppose that X and Y are discrete, with known PMFs, pX and pY . Then, pZ|Y(z|y)=pX(?). What is the argum...

Convergence in probability. For each of the following sequences, determine whether it converges in probability to a constant. If it does, enter the value of the limit. If it does not, enter the number “999". 1) Let X1, X2,… be independent continuous rando...

Find the limits Let Sn be the number of successes in n independent Bernoulli trials, where the probability of success at each trial is 1/3. Provide a numerical value, to a precision of 3 decimal places, for each of the following limits. You may want to re...

The sample mean Let X be a continuous random variable. We know that it takes values between 0 and 6, but we do not know its distribution or its mean and variance, although we know that its variance is at most 4. We are interested in estimating the mean of...

Airline overbooking For any given flight, an airline tries to sell as many tickets as possible. Suppose that on average, 20% of ticket holders fail to show up, all independent of one another. Knowing this, an airline will sell more tickets than there are...

Tossing a triple of coins We have a red coin, for which P(Heads)=0.4, a green coin, for which P(Heads)=0.5, and a yellow coin, for which P(Heads)=0.6. The flips of the same or of different coins are independent. For each of the following situations, deter...

By the argument in the last video, if the Xi are i.i.d. with mean μ and variance σ2 , and if Mn=(X1+⋯+Xn)/n , then we have an inequality of the form P(|Mn−μ|≥ϵ)≤aσ2n, for a suitable value of a . a) If ϵ=0.1 , then the value of a is: unanswered b) If we ch...

We saw that if we want to have a probability of at least 95% that the poll results are within 1 percentage point of the truth, Chebyshev's inequality recommends a sample size of n=50,000 . This is very large compared to what is done in practice. Newspaper...

CLT Let Xn be i.i.d. random variables with mean zero and variance σ2. Let Sn=X1+⋯+Xn. Let Φ stand for the standard normal CDF. According to the central limit theorem, and as n→∞, P(Sn≤2σn−−√) converges to Φ(a), where: a= unanswered Furthermore, P(Sn≤0) co...

CLT practice The random variables Xi are i.i.d. with mean 2 and standard deviation equal to 3. Assume that the Xi are nonnegative. Let Sn=X1+⋯+Xn. Use the CLT to find good approximations to the following quantities. You may want to refer to the normal tab...

CLT for the binomial Let X be binomial with parameters n=49 and p=1/10. The mean of X is: unanswered The standard deviation of X is: unanswered The CLT, together with the 1/2-correction, suggests that P(X=6)≈ unanswered You may want to refer to the normal...

Estimator properties We estimate the unknown mean θ of a random variable X (where X has a finite and positive variance) by forming the sample mean Mn=(X1+⋯+Xn)/n of n i.i.d. samples Xi and then forming the estimator Θˆ=Mn+1n. Is this estimator unbiased? u...

Bias and MSE We estimate the unknown mean θ of a random variable X with unit variance by forming the sample mean Mn=(X1+⋯+Xn)/n of n i.i.d. samples Xi and then forming the estimator Θˆn=13⋅Mn. Your answers below can be functions of θ and n. Follow standar...

Confidence interval interpretation Every day, I try to estimate an unknown parameter using a fresh data set. I look at the data and then I use some formulas to calculate a 70% confidence interval, [Θˆ−,Θˆ+], based on the day's data. Are the following stat...

A simple CI Let θ be an unknown parameter, and let X be uniform on the interval [θ−0.5,θ+0.5]. Is [X−2,X+2] an 80% confidence interval? unanswered I form a confidence interval of the form [X−a,X+a]. What is the narrowest confidence interval of this type (...

CI's via the CLT The sample mean estimate Θˆ of the mean of a random variable with variance 1, based on 100 samples, happened to be 22. The 80% confidence interval provided by the CLT is of the form [a,b], with: a= unanswered b= unanswered Your answers sh...

Natural estimators The random variables Xi are i.i.d. and satisfy E[X2i]=θ. Use a natural estimator to calculate an estimate of θ based on the values X1=1, X2=3, X3=−1, X4=2, X5=0. unanswered In order to calculate confidence intervals around your estimato...

ML estimation Let K be a Poisson random variable with parameter λ: its PMF is pK(k;λ)=λke−λk!,for k=0,1,2,…. What is the ML estimate of λ based on a single observation K=k? (Your answer should be an algebraic function of k using standard notation.) unansw...

Answers

The following answers were posted by visitors named SK.

Large atom goes on equatorial becasue equatorial is more stable than axial. You always want to have stable shape.

Thank you. I never thought about looking at them like money.

Is there an answer to this

What do you mean?

37.70 In this question, we're going to go step by step to get the final price of the share. We know that the stock started off as $40 per share, so that would be our starting value. The stock dropped by 10%, so let's calculate the drop in price. 40 · 0.10...