Answer Happy

65 points 1) Based on past history a Utility company knows that the amounts owed on its delinquent accounts are Normally distributed with a p- $25.10 and o = $7.33. i) a) If 16 Utility customers are chosen randomly, the probability that the mean amount owed for the 16 customers (i.e.) will be between $22.25 and $28.25 is b) The Standard Error of the Mean in this example is C) In order to answer a) and b) was it necessary to know that delinquent accounts are normally distributed? Explain ii) The Utility company's accountant has recently begun to sense that the average debt on delinquent accounts had changed (i.e. it is no longer $25.10) but still believes that o = $7.33. To check his suspicion, he did an audit of the company's books and found that for a randomly chosen sample of 16h sustomers i = $21.90. a) Fill in the appropriate H, and H.. Ho: H: b) Test this Hypothesis at a= .05 and clearly state your conclusion in English.

C) Describe in words what a B error in this example would be and its ramifications IV) Suppose the Utility company did not know what I had been in the past and also !! did not know what o was. Recently the Utility decided to get an Interval Estimate of p based on a sample of 16 customers with c = 30.25 and s = 8.62. a) Using the T distribution (why?) Calculate a 95% Confidence Interval for . b) Based on your CI could they conclude > 25.1?___Explain c) What is the Margin of Error for your Confidence Interval of part a)? 35 4 2) A bank wishes to make a forecast of its future check processing requirements. It has collected the following set of data. Month Number of Checks Processed in thousands 1 52 2 60 3 58 62 5 60 57 63 58 9 62 10 70 11 75 12 77 6 7 8 mmm 8mm四开门 i) Which is the Independent Variable and which is the Dependent Variable? Explain ii) In Excel draw the Scatter Diagram and Trend Line iii) The ANOVA printout for this problem is on the next page. Use it to answer a) The Coefficient of Determination is b) Explain what this means c) Give the Equation of the Trend Line d) Based on the trend line, how many checks would be expected to be processed in month 3?

SUMMARY OUTPUT Regression SSS Multiple R 0.85.2466 R Square 0.692966 Adjusted R Square 0.662263 Standard Error 4.347762 Observations 12 ANOVA Significanie ef 0.000779 Regression Residual Total SS MLS F 1426.636442676364 22.546373 10 189.0303 10.90303 11 615.6667 Cocin Standard Emo i Sad P-value 5160606 2675862 19.28577 3.06.09 1.727273 0.363578 4.750761 0.000779 Upper Lower Upper Lowey 955 95% 95.0 95.0 4564387 57.500 46,64007 SY56825 0.91717 2.537375 0.91717 2537375 Intercept Month