Q:  What is the range of periods of these Cepheids?

         The range is from

             log (P)  =  -0.1    -->   P =   0.8 days

         to

             log (P)  =  +1.9    -->   P =  79  days


         In other words, the periods range from 0.8 to 79 days,
         about a factor of 100!
 

  Q:  What is the range of magnitudes of these Cepheids?


         The apparent magnitudes in the K-band range from
         about K = 16 to K = 10, which is a range of 6 magnitudes.
         That corresponds to a factor of about 250 in brightness!