Chapter 12, Problem 12.5AC

The largest commercial fishing enterprise in the southeastern United States is the harvest of shrimp. In a study, researchers monitored variables thought to be related to the abundance of white shrimp. One variable the researchers thought might be related to abundance is the amount of oxygen in the water. The relationship between mean catch per tow of white shrimp and oxygen concentration was described by fitting a regression line using data from ten randomly selected offshore sites. (The "catch" per tow is the number of shrimp caught in a single outing.) Computer output is shown below. The regression equation is Mean catch per tow = -5855 + 97.4 O2 Saturation Predictor Coef SE Coef T P Constant -5855 2393 -2.45 0.040 O2 Saturation 97.4 34.62 2.81 0.023       c)Construct a 95% confidence interval for ?. (Use a table or technology. Round your answers to three decimal places.)   d)What margin of error is associated with the confidence interval in part (c)? (Round your…

The number of megapixels in a digital camera is one of the most important factors in determining picture quality. But, do digital cameras with more megapixels cost more? The following data show the number of megapixels and the price ($) for 10 digital cameras(Consumer Reports, March 2009). The Kodak Easy Share Z1012 IS digital camera has 10 megapixels. Predict the price of this camera using the estimated regression equation developed. Brand and Model Megapixels Price (S) Canon PowerShot SD1100 IS Casio Exilim Card EX-510 180 200 230 8 10 Sony Cyber-shot DSC-T70 Pentax Optio M50 Canon PowerShot G10 Canon PowerShot A590 IS Canon PowerShot El 8 120 470 15 140 180 310 250 10 Fujifilm FinePix FO0FD Sony Cyber-shot DSC-W170 Canon PowerShot A470 12 10 110

Isla Esme, Inc., sells tea products to various customers. In recent years, profits have been declining. The CFO of the business investigated the reasons for the profit decline and performed regression analysis for sales and costs. He determined that sales depend on product price, delivery speed, customer services, and marketing expenses. He also determined that total costs consist of variable costs of $25 per unit and fixed costs of $56,000. Marketing expenses have a coefficient of determination of 75% related sales.Question: Define the coefficient of determination and explain what it means in this scenario.

The following regression equation is based on the analysis of four variables:  SM_DOLLARS is the dollar amount of a watershed conservation agency's weekly spending on social media ads.  RADIO_ADS is the number of radio advertisements aired weekly by the agency.  WS_DOLLARS is the dollar amount of the agency’s weekly spending on web search ads.  The variable WEB_VISITS is the number of weekly visitors to their educational website.  These data have been recorded every week for the past three years.   WEB_VISITS (expected) = 208 + 1.5*SM_DOLLARS + 0.5*RADIO_ADS + 0.8*WS_DOLLARS   The data meet the assumptions for regression analysis, and the regression results, including the coefficients, were found to be statistically significant. How many additional weekly web visits would you predict when the agency increases its weekly spending on social media ads by $108 without changing the amount spent on radio ads or web search ads? (Round your answer to the nearest whole number.)