n Maatskappy stel daarin belang om te weet hoe duursaam die gereedskap is wat hulle vervaardig. Hulle maak 'n opname van 30 gereedskapstukke uit 30 verskillende afdelings. Vir elkeen van hierdie gereedskapstukke het hulle die volgende waardes waargeneem: /A tool manufacturing company would like to determine the durability of the tools manufactured by them. They decide to perform a survey on 30 tools from 30 different departments. For each one of these tools, the following variables are recorded:

y : Die lewensduur (in jare) van die gereedskapstuk na aanvang van gebruik /y : The lifetime (in years) of the tool measured from the day of first use.

x1 : Die kwaliteit van die onderdele wat gebruik is om die gereedskapstuk te vervaardig /x1: The quality of the parts used to manufacture the tool.

x2: Die hoeveelheid geld (in Rand) wat deur die afdeling van die maatskappy aangewend is om werkers te motiveer en samewerking te bevorder, bv. uitstappies in die wildtuin /x2: The amount of money (in Rand) invested by the department of the company to motivate employees and improve collaboration, e.g. trips to national parks.

x3: Die gemiddelde salaris (in Rand) van al die persone wat in die afdeling werksaam is /x3 : The average salary (in Rand) of employees working in the department.

Die onderstaande uitvoer is met behulp van Stat 1.2 verkry. Gebruik die uitvoer om die daaropvolgende vrae te beantwoord /The output below was generated by the multiple linear regression features in Stat 1.2. Use the output to answer the questions that follow.

Multiple Regression Output: y=₀ + ₁ x₁+₂ x₂+₃ x₃+ Variables y : ToolLife x1 : PQuality x2 : Motivate x3 : Salary

Number of observations: 30

Model Fitting Statistics R2 = 0.7211 Adj R2 = ?

Regression Coefficients Beta Parameter Standard b Parameter Standard Estimates Error of Beta Estimates Error of b t Statistic Prob > |t| Intcpt - 72.745 14.046 5.179 0.014 x1 4.600 0.172 0.481 0.180 2.676 0.263 x2 0.030 0.104 0.040 0.147 0.926 0.007 x3 - 0.435 0.172 0.253 0.100 - 2.526 0.212

Dui aan watter van die onafhanklike veranderlike(s) dra nie statisties betekenisvol by tot die model nie. Neem as 0.05 / Indicate which independent variable(s) does not contributestatistically significant towards the model. Take as 0.05.