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1666Exact Bootstrap Variance of a Two-Point MeanA sample is a,b . In the nonparametric bootstrap, a resample of size 2 is drawn with replacement. Derive the variance of the bootstrap sample mean.统计简单derivation未尝试免费1667Bootstrap Bias of the Sample Maximum on a Tiny SampleA sample is 1,4 . Under the nonparametric bootstrap with resample size 2, compute the bootstrap expectation of the sample maximum and the resulting bootstrap bias estimate for the original maximum statistic.统计简单derivation未尝试免费1668Bootstrap Variance of a Bernoulli Mean From the Plug-In LawA sample of size n has empirical success rate p hat. Under the nonparametric bootstrap, what is the variance of the resampled sample mean conditional on the observed data?统计简单derivation未尝试免费1669When the Bootstrap Median Is Forced to Equal One of Two ValuesA sample is 0,0,10 . Under the nonparametric bootstrap with resample size 3, what values can the bootstrap median take, and what condition determines which one occurs?统计中等derivation未尝试面试订阅1670m-out-of-n Bootstrap Variance Scaling for a MeanIf a statistic is the sample mean and you use an m-out-of-n nonparametric bootstrap instead of an n-out-of-n bootstrap, how does the conditional variance of the resampled mean scale with m?统计简单derivation未尝试免费1675Why the Basic Interval Reflects the Bootstrap Around the EstimateWhat conceptual idea makes the basic bootstrap interval differ from the percentile interval?统计中等essay未尝试面试订阅1681One-Sample z-Test with Known VolatilityA signal's average daily alpha over 25 days is 0.8, and the daily standard deviation is known to be 2. Test H 0: =0 against a two-sided alternative at the 5% level using a z-test.统计简单derivation未尝试免费1682One-Sided t-Test on a Small SampleFor n=10 independent observations, the sample mean is 1.5 and the sample standard deviation is 2. Test H 0: =0 against H 1: >0 at the 5% level using a t-test.统计简单derivation未尝试免费1683Two-Sample z-Test for Mean DifferenceTwo independent books produce average daily PnL of 102 and 100 over 100 days each. The daily standard deviation is known to be 5 for each book. Test whether the means are equal using a two-sided z-test.统计中等derivation未尝试面试订阅1684Chi-Square Goodness-of-Fit for a DieA six-sided die is rolled 60 times, and the counts are (14,8,11,9,10,8). Test fairness using a chi-square goodness-of-fit test.统计简单derivation未尝试免费1685Power of a One-Sided z-TestConsider testing H 0: =0 versus H 1: >0 with known =10 and sample size n=25 at significance level =0.05. What is the power when the true mean is =4?统计中等derivation未尝试面试订阅1686Sample Size for a z-TestYou want a two-sided z-test of H 0: =0 with known =4 to detect a true mean of 1 at 5% significance and 80% power. Approximately what sample size is needed?统计中等derivation未尝试面试订阅1687Paired t-Test on Trade-Cost DifferencesFor 16 paired executions, the mean cost difference (strategy A minus strategy B) is -1.2 and the sample standard deviation of the differences is 1.5. Test whether strategy A has lower mean cost using a 5% one-sided paired t-test.统计简单derivation未尝试免费1688Chi-Square Test for a Normal VarianceAssume normal data with n=20 and sample variance s 2=9. Test H 0: 2=4 using the classical chi-square variance test.统计中等derivation未尝试面试订阅1689Approximate Fair-Coin Test with a Normal ApproximationA coin is flipped 20 times and lands heads 14 times. Use the normal approximation to test fairness at the 5% two-sided level.统计简单derivation未尝试免费1690Likelihood-Ratio Test for an Exponential RateSuppose X 1,\dots,X 10 \sim Exp ( ) and X i=5. Use a likelihood-ratio test of H 0: =1 against the unrestricted alternative.统计困难derivation未尝试面试订阅1692Type I vs Type II Tradeoff from Changing a ThresholdA one-sided z-test for H 0: =0 with n=25 and known variance 1 rejects when X>c. Compare the thresholds c=0.33 and c=0.66 in terms of Type I error and power when the true mean is 0.5.统计困难derivation未尝试面试订阅1693Chi-Square Test of Independence in a 2x2 TableA 2x2 contingency table of outcomes is \begin pmatrix 30 & 20\\ 10 & 40\end pmatrix . Test independence using the classical chi-square test.统计中等derivation未尝试面试订阅1694One-Sided vs Two-Sided p-ValuesA test statistic is z=2.1 under a standard normal null. What are the one-sided and two-sided p-values, approximately?统计简单derivation未尝试免费1696Expected False Finalists After a Lookback FunnelA desk studies 30 genuinely null signals. For each signal it tries 4 lookback windows, advances the signal if any in-sample p-value is below 10%, and then requires a fresh holdout p-value below 5%. Assuming independence under the null, what is the expected number of false finalists?统计简单derivation未尝试免费