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Questions (39)

ML estimationLet 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
1. 2 answers
2. 1,873 views
Natural estimatorsThe random variables Xi are i.i.d. and satisfy E[X2i]=θ. Use a natural estimator to calculate an estimate of
1. 2 answers
2. 4,037 views
CI's via the CLTThe sample mean estimate Θˆ of the mean of a random variable with variance 1, based on 100 samples, happened
1. 1 answer
2. 3,167 views
A simple CILet 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%
1. 1 answer
2. 3,964 views
Confidence interval interpretationEvery day, I try to estimate an unknown parameter using a fresh data set. I look at the data
1. 1 answer
2. 4,143 views
Bias and MSEWe estimate the unknown mean θ of a random variable X with unit variance by forming the sample mean
1. 9 answers
2. 5,009 views
Estimator propertiesWe estimate the unknown mean θ of a random variable X (where X has a finite and positive variance) by
1. 1 answer
2. 4,014 views
CLT for the binomialLet X be binomial with parameters n=49 and p=1/10. The mean of X is: unanswered The standard deviation of X
1. 3 answers
2. 3,602 views
CLT practiceThe random variables Xi are i.i.d. with mean 2 and standard deviation equal to 3. Assume that the Xi are
1. 1 answer
2. 4,257 views
CLTLet Xn be i.i.d. random variables with mean zero and variance σ2. Let Sn=X1+⋯+Xn. Let Φ stand for the standard normal
1. 1 answer
2. 3,777 views
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,
1. 1 answer
2. 2,939 views
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
1. 2 answers
2. 2,962 views
Tossing a triple of coinsWe have a red coin, for which P(Heads)=0.4, a green coin, for which P(Heads)=0.5, and a yellow coin,
1. 0 answers
2. 1,333 views
Maximum likelihood estimationThe random variables X1,X2,…,Xn are continuous, independent, and distributed according to the
1. 2 answers
2. 2,022 views
Airline overbookingFor any given flight, an airline tries to sell as many tickets as possible. Suppose that on average, 20% of
1. 1 answer
2. 1,412 views
The sample meanLet X be a continuous random variable. We know that it takes values between 0 and 6, but we do not know its
1. 0 answers
2. 1,032 views
Find the limitsLet Sn be the number of successes in n independent Bernoulli trials, where the probability of success at each
1. 1 answer
2. 1,697 views
Convergence in probability.For each of the following sequences, determine whether it converges in probability to a constant. If
1. 1 answer
2. 3,055 views
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
1. 3 answers
2. 4,861 views
What is the conditional probability P(Heads|X=1/4)?
1. 0 answers
2. 2,885 views
For a given percentile range, what are the most ideal stock options to invest in for long-term growth?
1. 0 answers
2. 4,750 views
What is the probability that X and -Y sum to a negative value?
1. 0 answers
2. 3,109 views
9. Write a paragraph about the asteroid theory of dinosaur extinction. Be sure to include any geological evidence.
1. 1 answer
2. 780 views
1. How does chronic stress affect the reproductive system women?2. How might chronic stress affect the healing of a broken bone?
1. 2 answers
2. 945 views
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
1. 1 answer
2. 2,844 views
An electrician charges a customer $260 for 4 hours. He charges one customer $150 for 2 hours. How much does he charge for his
1. 1 answer
2. 566 views
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
1. 0 answers
2. 487 views
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
1. 1 answer
2. 515 views
Use the double angle formula to verify the identity cotxsin2x=1+cos2x
1. 0 answers
2. 1,160 views
Find the value of tangent of angle A, given cos2A = 4/5, and A terminates in quadrant 2
1. 2 answers
2. 644 views
find sin(s+t), given that sin t=1/3, t in quadrant 2, and cos s = -2/5, s in quadrant 3
1. 0 answers
2. 568 views
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
1. 0 answers
2. 574 views
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
1. 1 answer
2. 1,498 views
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
1. 1 answer
2. 907 views
A ship leaves its homeport and sails on a bearing of N28degrees10'E. Another ship leaves the same port at the same time and
1. 3 answers
2. 2,980 views
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
1. 1 answer
2. 3,921 views
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
1. 5 answers
2. 431 views
What is “institutional discrimination?” Give an example
1. 3 answers
2. 534 views
How would you purify decanoic acid contaminated with biphenyl? what method and solvent.Please help me
1. 1 answer
2. 726 views