change speed question

I am using the Audacity 2.1.1 , Mac Snow Leopard 10.6.8 and digitizing some old live cassette tapes and have a tape that plays one semitone higher than it should . The person who recorded it had a deck that ran faster. I.E. what should be in the key of C is playing in the key of C#
Does anyone know the numbers I would plug in to the change Speed panes who has already done this effect


The “Percent change” needs to be -5.613

Thanks so much Steve

If a problem of wrong speed happens again and it is easier to figure out the required pitch change than the required length change, you can obtain the required percent change by opening Effect > Change Pitch, select pitch “From” and “To” then read off the required percent change.

Don’t actually apply Change Pitch, because it does not change the tempo, only the pitch.