The missing value is 21.
The ratio value of the double number line is [tex]\frac{7}{2}[/tex].
Solution:
Ratio of the given number line is
[tex]$\frac{7}{2}=\frac{7\div1}{2\div1}=\frac{7}{2}[/tex]
[tex]$\frac{14}{4}=\frac{14\div2}{4\div2}=\frac{7}{2}[/tex]
[tex]$\frac{28}{8}=\frac{28\div4}{8\div4}=\frac{7}{2}[/tex]
[tex]$\frac{35}{10}=\frac{35\div5}{8\div5}=\frac{7}{2}[/tex]
Hence the common ratio of the number line is [tex]\frac{7}{2}[/tex].
The missing ratio is
[tex]$\frac{7}{2} =\frac{7\times3}{2\times3}= \frac{21}{6}[/tex]
Hence the missing value is 21.
