Instruction 18-4
a Manufacturer of Computer Disks Took Samples of 240

question 90

Short Answer

Instruction 18-4
A manufacturer of computer disks took samples of 240 disks on 15 consecutive days.The number of disks with bad sectors was determined for each of these samples.The results are in the table that follows.
$$\begin{array} { r c c } \text { Day } & \text { Bad } & \% \text { Bad } \\\hline 1 & 9 & 0.037500 \\2 & 7 & 0.029167 \\3 & 4 & 0.016667 \\4 & 6 & 0.025000 \\5 & 8 & 0.033333 \\6 & 3 & 0.012500 \\7 & 6 & 0.025000 \\8 & 10 & 0.041667 \\9 & 16 & 0.066667 \\10 & 24 & 0.100000 \\11 & 15 & 0.062500 \\12 & 9 & 0.037500 \\13 & 4 & 0.016667 \\14 & 8 & 0.033333 \\15 & 6 & 0.025000\end{array}$$
-Referring to Instruction 18-4,the best estimate of the mean proportion of disks with bad sectors is ________.

---

Definitions:

Concentrating Investment

Allocating a significant portion of an investment portfolio to a single investment or a small group of investments, increasing potential risk and return.

Systematic Risk Principle

The concept that the overall market or economy has inherent risks that affect all investments to some degree, and these risks cannot be eliminated through diversification.

Variance

A measure of the dispersion or spread of a set of data points or investment returns, reflecting how much the data points differ from the mean.

Beta

A metric that evaluates the degree of fluctuation in a stock's price against the broader market.