Answer to Question #271120 in Civil and Environmental Engineering for Deshi

Question

A mountain climber plans to buy some rope to use as lifeline. Which of the following would be the better choice? Explain your choice.

Rope A: Mean breaking strength:500lb; standard deviation of 100lb

Rope B: Mean breaking strength: 500lb; standard deviation of 10lb

Answer 1

Given :

Rope A: Mean breaking strength: 500 lb; standard deviation of 100 lb

Rope B: Mean breaking strength: 500 lb; standard deviation of 10 lb

We have to find which rope is better choice to use as a lifeline.

 

Solution:

Standard deviation tells about the spread of data from the mean value. If it is large, there is more spread of data from the mean value and when standard deviation is small, the remaining points are close to the mean value.

So, data which has smaller standard deviation is better choice to pick always.

Rope A and B have same mean breaking strength :500 lb

So, the better choice depends upon the standard deviation of ropes

A high standard deviation indicates that the data is widely spread (less reliable) and

A low standard deviation indicates that the data are closely clustered around the mean (more reliable).

Here Rope B has less standard deviation when compared to Rope A

Therefore, Rope B is more reliable and it is the better choice for using as a lifeline