5. Consider the OLS estimator of a model to explain the stock prices of a FTSE 100 company using 120 observations from 2012 m1 to 2021 m 12, all variables are calculated at the end of the month t: log (stock +) 0.86 + 0.54 log (profit £) - 0.65 log (research t)-1.34 log (marketing &) (1.12) (0.24) (20)

A survey was conducted and asked: "Do you consider your health to be poor?" This was coded as 1 for "yes" and 0 for "no." The effect of age (in years) and sex (1 male, 0 = female) on the outcome was examined using logistic regression. The fitted logistic model is: = logit(ô) = −0.544 + ß * sex + 0.0331 * age (a) What are the odds of responding "yes" for a female subject who is 60 years old? (b) What is the estimated odds ratio corresponding to the age variable? Interpret this estimate. (c) Suppose that, based on the data from the survey, the odds of responding "yes" for males are 3.79% greater than the odds for females, adjusting for age. What is the value of Â? (d) If we only wanted to assess the association between survey response (yes/no) and sex, what other method(s) (that we have learned in this class) could we have used (name at least one)? In your own words, explain why we cannot use the same method(s) if we want to consider the effects of both sex and age on survey response.

Exercise 9. Suppose that the lifespan (in years) of a water heater is modeled as Y - Expon(mean = 8). (a) Given that the unit is working at 3 years, compute the chances it will fail in the next year. (b) Given that the unit is working at 18 years, compute the chances it will fail in the next year. (c) Comment on the reasonableness of this Exponential model.

PQ3

Suppose sales for the past 6 months have been100, 90, 84, 113, 92, and 96 Using a smoothing coefficient of 0.5, what is the exponentially smoothed value for the 4th period? (please round your answer to 1 decimal place)

please answer these two correctly;

Here's a table with average monthly price of a stock from Jan 2021-July 2021. Month Price Jan 29000 Feb 27000 Mar 31000 Apr 30000 May 32000 June 28000 July 29000 Using a 3-period weighted moving average with weights (wt, wt-1, W-2) = (0.6, 0.2, 0.2), the predicted price August is Using an exponential smoothing model with = 0.4, and with the initial predicted price for Jan the same as the observed price for January, the predicted price for August is % Now, let's suppose that we finally observe that the price for August is 30000. The absolute percent error (APE) of your prediction for August is using the weighted moving average method and % using the exponential smoothing model. (Note: Round your answer to the nearest 2 decimal places. For your APE answer for example let's say you get 0.06786 from Excel, then you should type-in 6.79 as your answer here since it is represented as percentage. Do not enter any symbols other than integers and decimal.)

14. This table shows the growth in the number of free wireless Internet access points in a city. Year 2006 2007 Number of access points 2003 2004 29 46 119 190 Determine the exponential relation y = ab* that best fits the data, where x is the number of years since 2003. a. y = 29(1.4)* b. y 18(1.8)* C. y = 18(1.8)* d. y = 29(1.6) 15. This table shows the decay in mass of a radioactive 5 15 Time (days) Mass (mg) 159 81 10 114 2005 74 Estimate the mass of the element after 45 days. a. About 15 mg b. About 11 mg 20 58 C. element. 25 41 About 21 mg E OF d. About 8 mg

One of the possible models for the coronavirus is the logistic curve, shown here without scale. This curve shows the total number of cases of people infected with the virus. The rate of change for this curve is the number of ca es per day. 1. On the curve, mark the point at which the number of cases per day is greatest. What is a mathematical term for this point? 2. One of the criteria for re-opening activities is fourteen consecutive da s with a decreasing number of cases. Where is this on the curve? Number of Infected people as a function of time