It is well documented that a typical washing machine can last anywhere between 5 to 20 years. Let the life of a washing machine be represented by a lognormal variable, Y = e^X where X is normally distributed. In addition, let the mean and standard deviation of the life of a washing machine be 11 and half years and 2 years, respectively. [You may find it useful to reference the z table.]

b. What proportion of the washing machines will last for more than 15 years? (Round your intermediate calculations to at least 4 decimal places and final answer to 4 decimal places.) c. What proportion of the washing machines will last for less than 8 years? (Round your intermediate calculations to at least 4 decimal places and final answer to 4 decimal places.) d. Compute the 80th percentile of the life of the washing machines. (Round your intermediate calculations to at least 4 decimal places and final answer to the nearest whole number.)

TABLE 1 Standard Normal Curve Areas Entries in this table provide cumulative probabilities, that is, the area P ( ZS- Z) under the curve to the left of -Z. For example, P(Z