Statistic Homework

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  • Topic: Chi-square distribution, Regression analysis, Time series analysis
  • Pages : 4 (1470 words )
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  • Published : June 5, 2011
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統計學 HW7
選擇題(每題 5 分,共 105 分)


1. Economic periods of prosperity followed by recession are described as: A. Secular trend B. Seasonal variation C. Cyclical variation D. Erratic variation 2. The following linear trend equation was developed for annual sales from 1995 to 2001 with 1995 the base or zero year. = 500 + 60t (in $thousands). What are the estimated sales for 2005 (in $thousands)? A. $500 B. $560 C. $1,040 D. $1,100 3. Which one of the following is not a component of a time series? A. Secular trend B. Moving average C. Seasonal variation D. Irregular variation E. All of the above are components 4. The possible values for the Durbin-Watson statistic are A. any value B. any value greater than zero C. any value from 0 to 4 inclusive D. any value less than zero. 5. A question has these possible choices—excellent, very good, good, fair and unsatisfactory. How many degrees of freedom are there using the goodness-of-fit test to the sample results? A. 0 B. 2 C. 4 D. 5

6. What is the critical value at the 0.05 level of significance for a goodness-of-fit test if there are six categories? A. 3.841 B. 5.991 C. 7.815 D. 11.070 7. What is our decision regarding the differences between the observed and expected frequencies if the critical value of chi-square is 9.488 and the computed value is 6.079? A. The difference is probably due to sampling error; do not reject the null hypothesis B. Not due to chance; reject the null hypothesis C. Not due to chance; do not reject the alternate hypothesis D. Too close; reserve judgment 8. The chi-square distribution is A. positively skewed. B. negatively skewed. C. normally distributed. D. negatively or positively skewed. 9. Two chi-square distributions were plotted on the same chart. One distribution was for 3 degrees of freedom and the other was for 12 degrees of freedom. Which distribution would tend to approach a normal distribution? A. 3 degrees B. 12 degrees C. 15 degrees D. All would 10. If the...
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