本金為什么不變？
如果取22度的概率是0 同時(shí)在20到25度 取到任何一個(gè)數(shù)值的概率是一樣的 也是1/N 但1/N是無限接近0 是不是可以說取到任何一個(gè)數(shù)的可能性也是0？
請(qǐng)問用計(jì)算器算b0,b1時(shí)，如果用b1的公式，那么分母：x的方差，是sx還是seita x呢？
①這個(gè)題目怎么通過計(jì)算的方式得到？
請(qǐng)問用計(jì)算器算攤銷的方法需要掌握嗎？
data snooping bias老師講的時(shí)候說有個(gè)題眼叫“repeatedly searching"，重復(fù)研究為什么不算是sample selection bias？
精 答疑題目，請(qǐng)見截圖1
精 老師，A選項(xiàng)什么意思
教材P246-Example 2-Solution to 2-最后兩句話中的數(shù)據(jù)from 1.769 to 2.231，以及from 1.538 to 2.462，這4個(gè)數(shù)據(jù)是題目中給定的數(shù)據(jù)，還是自己計(jì)算得出的數(shù)據(jù)？
Find the reliability factors based on the t-distribution for the following confidence intervals for the population mean (df = degrees of freedom, n = sample size): A.A 99% confidence interval, df = 20 A 90% confidence interval, df = 20 C. A 95% confidence interval, n = 25 D. A 95% confidence interval, n = 16 A. For a 99% confidence interval, the reliability factor we use is t0.005; for df = 20, this factor is 2.845. B. For a 90% confidence interval, the reliability factor we use is t0.05; for df = 20, this factor is 1.725. C. Degrees of freedom equals n ? 1, or in this case 25 ? 1 = 24. For a 95% confidence interval, the reliability factor we use is t0.025; for df = 24, this factor is 2.064. D. Degrees of freedom equals 16 ? 1 = 15. For a 95% confidence interval, the reliability factor we use is t0.025; for df = 15, this factor is 2.13 課后答案中的t0.005 t0.05 t.0.025 t0.025這幾個(gè)數(shù)是怎么來的？
請(qǐng)問市場(chǎng)上什么時(shí)候是真的會(huì)連續(xù)復(fù)利計(jì)息的呢？
A portfolio has an expected mean return of 8% and standard deviation of 14%. The probability that its return falls between 8% and 11% is closest to: A. 8.5%. B. 14.8%. C. 58.3%. 這題我查表得出的0.5832，課后答案查表得出的是58.48%，（我查的是累積分布表上的數(shù)值）我錯(cuò)在哪個(gè)地方？
B如何理解？
這題中A為什么是錯(cuò)的？
Suppose the prospects for recovering principal for a defaulted bond issue depend on which of two economic scenarios prevails. Scenario 1 has probability 0.75 and will result in recovery of $0.90 per $1 principal value with probability 0.45, orin recovery of $0.80 per $1 principal value with probability 0.55. Scenario 2 has probability 0.25 and will result in recovery of $0.50 per $1 principal value with probability 0.85, or in recovery of $0.40 per $1 principal value with probability 0.15. A. Compute the probability of each of the four possible recovery amounts: $0.90, $0.80, $0.50, and $0.40. B. Compute the expected recovery, given the first scenario. C. Compute the expected recovery, given the second scenario. D. Compute the expected recovery. E. Graph the information in a probability tree diagram. 圖為我做題的過程，B、C、D這三問題，算出來的結(jié)果跟答案不一樣？我到底錯(cuò)在哪個(gè)地方？
程寶問答
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