Check whether the following terms are in proportion.

$3,5,6,10$

Check whether the following terms are in proportion.

$4,8,7,14$

Check whether the following terms are in proportion?

$4, 8, 7, 14$

Check whether the following terms are in proportion?

$2, 12, 3, 18$

Check whether the following terms are in proportion? or not ?

$10, 12, 15, 18$

Check whether the following terms are in proportion? or not ?

$11, 16, 16, 21$

Check whether the following terms are in proportion? or not ?

$8, 13, 17, 19$

Check whether the following terms are in proportion? or not ?

$30, 24, 20, 16$

Write true or false.

$4:2::14:7$