Math lovers HELP!: Need assistance figuring out what's wrong with our electric bill problem...?

Question

Current Electric Bill
23 May to 23 June: $339.96
$339.96/31 days = $10.97/day
2 ppl = $5.49
3 ppl = $3.66
4 ppl = $2.74
5 ppl = $2.19

MC 23 May to 05 June = 14 days
DR 07 June to 23 June = 15 days
JR 23 May to 23 June = 31 days
LW 23 May to 23 June = 31 days
JB 20 June to 23 June = 4 days

23 May to 05 June = 14 days = 3 people (JR, MC, LW) = $3.66/day
05 June to 07 June = 3 days = 2 people (JR, LW) = $5.49/day
08 June to 19 June = 12 days = 3 people (JR, LW, DR) = $3.66/day
20 June to 23 June = 4 days = 4 people (JR, LW, DR, JB) = $2.74/day

JR:
14 days @ $3.66 = $51.24
3 days @ $5.49 = $16.47
12 days @ $3.66 = $43.92
4 days @ $2.74 = $10.96
$122.59

LW:
14 days @ $3.66 = $51.24
3 days @ $5.49 = $16.47
12 days @ $3.66 = $43.92
4 days @ $2.74 = $10.96
$122.59

MC:
14 days @ $3.66 = $51.24
$51.24

DR:
12 days @ $3.66 = $43.92
4 days @ $2.74 = $10.96
$54.88

JB:
4 days @ $2.74 = $10.96
$10.96

GRAND TOTAL:$362.26...Why the discrepancy?

Answer 1

OK. First, lets get these numbers right. I'm assuming all your dates are inclusive. By this I mean that when someone is there from May 23 to May 24, they get billed for 2 days.

This means 32 days total including May 31st.

23 May to 23 June: $339.96
$339.96/32 days = $10.62375/day
2 ppl = $5.31
3 ppl = $3.54
4 ppl = $2.66
5 ppl = $2.12

MC 23 May to 05 June = 14 days
DR 07 June to 23 June = 17 days
JR 23 May to 23 June = 32 days
LW 23 May to 23 June = 32 days
JB 20 June to 23 June = 4 days

I'm not going to do the intermediate math for you, but I'll give you a hint, use Excel.

Here's the bottom line:
MC = $49.58
DR = $56.66
JR = $111.55
LW = $111.55
JB = $10.62

Grand Total = $339.96

Answer 2

Without looking at all the math, I see one problem right off the bat - May 23-June 23 is 32 days inclusive, not 31. 31 days would be from May 23 to June 22. Count it out if you must, but you can think of it this way - from May 1 to June 1 is 31 days of May plus 1 day of June for a total of 32 days.

That will have the net effect of lowering your daily amount.

Answer 3

That is very anal.

You electricity is billed by kilowatt-hour, not by person. It's virtually impossible to accurately break down a bill the way that you have.

What were the people using (as far as electrical items) per day and for how long? This not only includes the curling irons and electric shavers but the lights, the heat, the fridge, the computer and accessories. Were any windows open while the HVAC system was running? Does the HVAC system need a filter?

See what I mean...it's not a linear breakdown per person.