Question

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The number of students in 40 schools in a certain sub-county were recorded as follows:  
         238  100  173  115  398  597  572  299  
         255  750  587  403  250  217  797  386  
         362  486  453  279  436  248  780  316  
         529  305  372  286  842  235  420  492  
         226  245  695  720  267  617  198  830  

1. Complete the frequency distribution table below for the data. 

   Number of students	100-199	200-249	250-399	400-599	600-799	800-849
   Number of schools

2. draw a histogram to represent the data. 
        
3. Use the histogram to estimate the:  
   • median; 
   • number of schools with more than 350 students.  

Answer 1

1. class	tally	f	fd	cf
   100-199	llll	4	0.04	4
   200-249	llll l	6	0.12	10
   250-399	llll llll ll	12	0.08	22
   400-599	llll llll	10	0.05	32
   600-799	llll l	6	0.03	38
   800-849	ll	2	0.04	40

2. 
   
3.  
   • Median psn=⁴⁰/₂ =20th value
        =10 + x × 0.08 = 20
     x = 125
     Median = 125+249.5
     =374.5
   • 49.5 × 0.08 + 10 + 6 + 2
     = 21.96
     ≈ 22 schools