Normal Model

Question 1

The mean life of a certain brand of auto batteries is 44 months with a standard deviation of 3 months. Assume that a Normal model can be applied.

a) Draw the model for the life of the auto batteries. Clearly label it, showing what the 68-95-99.7 rule

predicts.

b) In what interval would you expect the central 68% of life of batteries to be found?

c) About what percent of batteries should get more than 47 months of life?

d) About what percent of batteries have life between 47 and 50 years?

e) Describe the life of the worst 2.5% of all batteries?

f) About what percent of batteries have life between 45 and 51 years?

g) Find the life of the best 7% of all batteries?

Question 2

“The Malaysian economy expanded strongly by 5.9% during the fourth quarter of 2017 (Q4 2016: 4.5%). Growth was supported by domestic demand, particularly private sector spending. On the supply side, all sectors registered a positive growth except mining and quarrying. For the year, the economy grew 5.9% (2016: 4.2%), surpassing the earlier estimation of 5.2% – 5.7%.

Based on the above statement:

•  explain the factors that have influenced the economic direction of Malaysia;
•  analyse the policies adopted by the Malaysian government to achieve the above growth rate.