Normal Distribution and Z Scores

[11stuck]

The lengths of sunfish in a pond are normally distributed. Find the mean and standard deviation if 91% of these fish have a length between 13.2cm and 17.7cm.

 

[Deleted member 4993]

The lengths of sunfish in a pond are normally distributed. Find the mean and standard deviation if 91% of these fish have a length between 13.2cm and 17.7cm.

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[Steven G]

Can this be done without know which 91% they are talking about?

 

[Dr.Peterson]

Can this be done without know which 91% they are talking about?

Good point.

@11stuck, did you give us the complete problem, word for word? Does the actual problem state in some way, say, that it's the middle 91%, and not, say, the top 91%?