Question

[walker8476]

I have this problem but I'm not sure about the solution:

 

[stapel]

I have this problem but I'm not sure about the solution:

\(\displaystyle x\, =\, 2.35\sigma\)

\(\displaystyle x\, =\, 0.15\)

\(\displaystyle \mbox{Solve }\, \sigma\)

\(\displaystyle 0.15\, =\, 2.35\sigma\)

\(\displaystyle \dfrac{0.15}{\sigma}\, =\, 2.35\)

Um... Why are you "solving" like this? If you'd been given "6 = 3y", would you really divide through by the y, rather than by the 3...?

 

[walker8476]

Um... Why are you "solving" like this? If you'd been given "6 = 3y", would you really divide through by the y, rather than by the 3...?

Oh yeah. I have no idea why I did it like this. Ok how about now?

 

[stapel]

Oh yeah. I have no idea why I did it like this.

\(\displaystyle x\, =\, 2.35\sigma\)

\(\displaystyle x\, =\, 0.15\)

\(\displaystyle \mbox{Solve }\, \sigma\)

\(\displaystyle 0.15\, =\, 2.35\sigma\)

\(\displaystyle \dfrac{0.15}{2.35}\, =\, \sigma\)

\(\displaystyle 0.64\, =\, \sigma\)

Ok how about now?

You're dividing something (0.15) that is way less than 1/4 by something (2.35) that is larger than 2. So your result should be something smaller than (1/4)/2 = 1/8. Your answer is much larger than that. Your set-up is good, but you might want to check your arithmetic.

 

[walker8476]

You're dividing something (0.15) that is way less than 1/4 by something (2.35) that is larger than 2. So your result should be something smaller than (1/4)/2 = 1/8. Your answer is much larger than that. Your set-up is good, but you might want to check your arithmetic.

Oh, should be 0.064