Monday

March 30, 2015

March 30, 2015

Posted by **bennett** on Friday, July 24, 2009 at 7:16am.

a. Using the day as the x-value and the closing value as the y-value, write equations in slope-intercept form for the lines that represent each value change.

b. What would indicate that the rate of change for two pair of days was the same? Was the rate of change the same for any of the days shown?

c. Use each equation to predict the closing value for the next business day (Day 22). The actual closing value was 1909.90. Did any equation correctly predict this value? Explain.

Stock Index

March, 2004

______________________

Day - Closing Value

15 - 1939.20

16 - 1943.09

17 - 1976.76

18 - 1962.44

19 - 1940.47

- precalc -
**Damon**, Friday, July 24, 2009 at 8:52amfor each pair do

y = m x + b

for example for day 15 and 16

1939.2 = m (15) + b

1943.9 = m (16) + b

------------------------ subtract

- 4.7 = -1 m

so

m = 4.7 - slope That is the "rate of change" for part b

back for b value

1939.2 = (4.7)(15) + b

b = 1868.7

so for the first two points the line is

price = 4.7*day + 1868.7

for the day 22

price = 4.7*22 + 1869.7

= 1973.1

The actual price on day 22 was 1909.9

There is no reason any combination of the prices of the previous week should predict the price on Monday. It happened that the price was going up fast between Monday and Tuesday. All we just did was assume that it continued to go up like that for a week, which it did not do.

- precalc -
**bennett**, Friday, July 24, 2009 at 8:59amthanks

**Answer this Question**

**Related Questions**

math - The table shows the closing value of a stock index for one week in March...

math (pre-calc) - Analyzing a Stock. The beta, B of a stock represents the ...

Algebra - The table below shows the opening value of a stock on the first day of...

Algebra - The table below shows the opening value of a stock on the first day of...

precalc - Suppose the value of quantity A changes from a starting value of x to...

Sttistic - tobt = 1.49. Report the statistical results using the correct format...

math - A share of stock worth 100 dollars loses 90% of its value. Then, over ...

Math - A share of stock worth 100 dollars loses 90% of its value. Then, over the...

math - slope-intercept - How do I write one equations in slope-intercept form, ...

math - A stock that sold for $240 per share before a week began had the ...