Ray's New Higher Arithmetic · Arts. 270–273 · Unit 16: Percentage: Applications without Time (continued)
73. Stock investments: Cases II to V
Goal: Your student finds the dividend rate, the amount to invest, the rate of income, and the market price that gives a wanted rate of income.
You'll need
- The book
- A slate, small whiteboard or scrap paper
- A notebook and pencil
What's in the book
Case II (rate of dividend), Case III (amount invested), Case IV (rate of income) and Case V (market value), each with a worked problem and examples. Most answers are printed.
The lesson, step by step
Warm-up
Review Case I: $1900 invested in 6% stock at 95. ($1900 ÷ .95 = $2000 par; income $120.)
Case II: the dividend rate
Invested $10132.50 in railroad stock at 105%, which pays me annually $965: what is the rate of dividend on the stock?
$10132.50 ÷ 1.05 = $9650 of par; $965 ÷ $9650 = 10%.
Case III: how much to invest
If U. S. bonds, paying 5% interest, are selling at 108½%, how much must be invested to secure an annual income of $2000?
$2000 ÷ .05 = $40000 of par; at 108½% it costs $40000 × 1.085 = $43400.
Case IV: rate of income
What per cent of his money will a man realize in buying 6% stock at 80%?
Each 80 cents buys $1 of stock paying 6 cents: $.06 ÷ $.80 = 7½%.
Try together:
What is the rate of income on Pacific Mail 6's, bought at 30?
Case V: the right price
Read the book's solution:
What must I pay for Lake Shore 6's ($100 a share), that the investment may yield 10%?
If bought for $100, or par, it will yield 6%; to yield 1% it must be bought for $100 × 6 = $600; to yield 10% it must be bought for 1/10 of $600 = $60.
Independent practice
Your student picks two examples from each case. Include Case V, Example 2 (the one without a printed answer):
Which is the best permanent investment: 4's at 70%, 5's at 80%, 6's at 90%, or 10's at 120%? Why?
Wrap-up
Ask: Which pays more on your money, 6% stock bought at 80 or bought at 120? (At 80: 7½% against 5%.)
Afterwards
This is a big lesson. Split it: Cases II and III one day, Cases IV and V the next.
Answers to the book's problems
Case V, Ex. 2 (no printed answer): rate of income = dividend ÷ price. 4's at 70: 5 5/7%; 5's at 80: 6¼%; 6's at 90: 6⅔%; 10's at 120: 8⅓%. The 10's at 120% are the best, because they pay the most on the money invested.
Worked out for this site from the scan. If a number in your copy differs, trust the book.