Exam 4: Percents, Averages, and Estimates

Carry the answer to two decimal places. Solderless lugs are quoted at $42.50 less 40% for standard packages of 50. What will be the cost if only 22 are ordered at list price less 35%?

Carry the answer to two decimal places. A 208-volt, 4-wire, 3-phase wye power system feeds a school building. Daily voltage readings taken for one week are 205.25 volts, 203.75 volts, 208 volts, 204.35 volts, 206.7 volts, 207 volts, and 208.55 volts. What is the average daily voltage of the system? Round the answer to the nearer hundredth.

Carry the answer to two decimal places. Find the average of the following measurements: 17 inches, 16 inches, 18 inches, 21 inches, 29 inches, and 24 inches. Round the answer to the nearer hundredth.

A firm purchases several motors at a cost of $8,350 and gives a note bearing an 8% interest rate per annum. The note is due one year later. What is the total amount to be paid on the note?

A 12-volt battery has had a capacity of 30 ampere-hour aging and has dropped to a capacity of 24 ampere-hours. Find the percent decrease in capacity.

A contractor purchases a truck for $16,800 and is allowed $2,000 for trading in an old truck. A cash deposit of $200 is made. How much interest is paid for one year at a rate of 12% per annum?

A shipment of 15 heat pumps arrives for storage at an electrical supply house. The pumps cannot be stacked, and each has a base measurement of 3.2 feet by 3.8 feet. A storage area 14 feet long and 12 feet wide is available. Is there sufficient space to store the shipment?

Carry the answer to two decimal places. A motor rated at 90 horsepower is actually developing 105 horsepower. What is the percent of horsepower overload?

Carry the answer to two decimal places. An electrician borrows $2,750 at 9.7% interest rate per annum to purchase electrical supplies. If the loan is repaid in 15 months, how much is the interest?

If $168.00 is the profit on a job, and this represents 8% of the contract price, what is the contract price?

A contractor purchases motors listed at $6,800 and receives successive discounts of 20% and 10%. What is the net cost?

An electrician purchases a new truck for the amount shown. He trades in an old truck and pays an amount of money in cash toward the total payment. When the loan is paid in full after one year, what will it cost in interest payments?

Carry the answer to two decimal places. In replacing 55 lamp bulbs, an apprentice breaks 6. Find to the nearer hundredth percent the percent broken.

Carry the answer to two decimal places. Find, to the nearer hundredth horsepower, the amount of input horsepower required for the machine shown if it is to deliver an output of 97 horsepower. $X _ { L } = \sqrt { Z ^ { 2 } - R ^ { 2 } }$

Carry the answer to two decimal places. A contractor purchases quantities of wire, fittings, and switches listed at $2,150 at Successive trade discounts of 15%, 10%, and 3%. What is the net cost? $E _ { C }$

Carry the answer to two decimal places. Workers receiving $124.60 per day have their wages increased by 8%. How much is received per day after the increase?

Carry the answer to two decimal places. An electrician borrows $1,250 at 12.5% interest rate per annum to replace direct current motors with alternating current motors. The loan is paid back in 1 year and 2 months. Find the amount of interest.

Carry the answer to two decimal places. Two-inch angle iron weighing approximately 2.97 pounds per foot is used to build panel-mounting racks. These amounts of iron are used: panel A, 9 feet; panel B, 10.75 feet; panel C, 8.6 feet; and panel D, 7.7 feet. What is the average weight per panel? Round the answer to the nearer hundredth.

Carry the answer to two decimal places. An electrical supply uses the following wattages: 4,212 watts, 4,226 watts, 4,296 watts, 3,427 watts, 914 watts, 1,428 watts, and 4,293 watts. What is the average wattage used? Round the answer to the nearer hundredth.

When mixing a quantity of electrolyte for a storage battery, the electrician uses 2 parts of acid and 3 parts of water. What percent is acid?