Can you please help me

1.

1 out of 10 of 500 customers is 50 customers surveyed.  So there must be 20 who choose 3-D.

20

2. The every 10th part is fine; it's the Sunday afternoon that makes this a representative sample of folks who show up on Sunday, but maybe one for entire week.  Presumably we get more kids on Sunday afternoon than a weekday evening, for example.

No

3. 100:25 = 12:x so x = 25*12/100 = 3

3

Real surveys get answers from who they reach and then try to correct for the undersampling or oversampling of some group after the data's been collected.

4. weekday:total = 40:40+80  = 400:x

x = 400(40+80)/40 = 1200

1200

ok

step-by-step explanation: