The hourly error rate for this machine is the error rate in parts per 100 multiplied by the number of parts produced per hour:

\( \frac{4}{100} \) x 5 = \( \frac{4 \times 5}{100} \) = \( \frac{20}{100} \) = 0.2 errors per hour

So, in an average hour, the machine will produce 5 - 0.2 = 4.8 error free parts.

The machine ran for 24 - 5 = 19 hours yesterday so you would expect that 19 x 4.8 = 91.2 error free parts were produced yesterday.

The equation for this sequence is:

a_n = a_n-1 + 2(n - 1)

where n is the term's order in the sequence, a_n is the value of the term, and a_n-1 is the value of the term before a_n. This makes the next number:

a₆ = a₅ + 2(6 - 1)
a₆ = 21 + 2(5)
a₆ = 31

To fill a 6 gallon tank exactly halfway you'll need 3 gallons of fuel. Each fuel can holds 1 gallons so:

cans = \( \frac{3 \text{ gallons}}{1 \text{ gallons}} \) = 3

In order to find how many additional workers are needed to staff the extra crews you first need to calculate how many workers are on a crew. There are 4 workers at the company now and that's enough to staff 2 crews so there are \( \frac{4}{2} \) = 2 workers on a crew. 4 crews are needed for the busy season which, at 2 workers per crew, means that the roofing company will need 4 x 2 = 8 total workers to staff the crews during the busy season. The company already employs 4 workers so they need to add 8 - 4 = 4 new staff for the busy season.

44% of the water consumption is industrial use and 34% is personal use so (44% - 34%) = 10% more water is used for industrial purposes. 10,000 gallons are consumed daily so industry consumes \( \frac{10}{100} \) x 10,000 gallons = 1,000 gallons.