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Maximum likelihood

1.[2p]

What does the likelihood L(θ) measure?

Correct
The answer is: How probable the observed data is, read as a function of $\theta$
The answer is: How probable the observed data is, read as a function of $\theta$
The answer is: How probable the observed data is, read as a function of $\theta$

2.[1p]

A coin gives 60 heads in 100 tosses. What is the maximum likelihood estimate of p?

CorrectNot quite: 0.6

3.[2p]

In 400 voters, 240 support a proposal. What is the standard error of pˆ, to four decimal places?

CorrectNot quite: 0.0245

4.[2p]

200 corps-years of Prussian cavalry records contain 122 deaths from horse kicks. What is the maximum likelihood Poisson rate per corps-year?

CorrectNot quite: 0.61

5.[3p]

Match each model to its maximum likelihood estimator.

  • Bernoulli p

  • Poisson λ

  • Exponential rate λ

  • Uniform upper limit θ

  • the sample maximum

  • the sample mean

  • one over the sample mean

  • the sample proportion k/n

Show the answer

Bernoulli p: the sample proportion k/n Poisson λ: the sample mean Exponential rate λ: one over the sample mean Uniform upper limit θ: the sample maximum

6.[2p]

The maximum likelihood estimator of σ2 for a normal sample divides the sum of squared deviations by n, and is therefore biased low.

Correct
The answer is: True

7.[3p]

Why is the curvature of the log likelihood at its maximum related to the standard error?

Correct
The answer is: A sharp peak means nearby parameter values fit much worse, so the data pins $\theta$ down tightly
The answer is: A sharp peak means nearby parameter values fit much worse, so the data pins $\theta$ down tightly
The answer is: A sharp peak means nearby parameter values fit much worse, so the data pins $\theta$ down tightly

8.[2p]

From pˆ=0.6, what is the maximum likelihood estimate of the odds p/(1-p)?

CorrectNot quite: 1.5

9.[3p]

Where does the standard large-sample theory of maximum likelihood break down?

Select all that apply

Correct
Correct
Correct
The answer is: When the range of possible data values depends on the parameter, as for a uniform upper limit, When the sample is small, so that asymptotic results have not taken effect, When one group in a logistic regression has no failures, giving an infinite maximum