linear transformation model help
Number of months Number of fish 0 8 1 39 2 195 3 960 4 4,738 5 23,375
log y hat=0.9013x+0.6935
Use the linear transformation model to predict the number of fish in 12 months.
i got 5,685,367
@atreyu6s3x6
haha sorry im bad at prob and stats
The model is way off even at 5 months. Can you double-check the model?
i think @mathmate has it haha
hmmm thats what i got
(log y hat=0.9013•logx+ 0.6935 ) this the other model thats is the closest to the one i have
but im pretty sure my log is correct
I have this question and the other one @atreyu6s3x6 tried helping me with. i can show you the entire part of the lesson if you need it.
Scientists are studying the population of a particular type of fish. The table below shows the data gathered over a five–month time period. Use the data to answer questions 5–9. Number of months Number of fish 0 8 1 39 2 195 3 960 4 4,738 5 23,375 5. What does the scatterplot of the data show? (1 point) • a strong positive linear relationship • a strong negative linear relationship • a curve that represents exponential growth * • a curve that represents exponential decay 6. Complete an exponential transformation on the y-values. What is the new value of y when x = 5? (1 point) • 4.3688 • 3.6756 * • 0.6990 • 3.3757 7. Find the linear transformation model. (1 point) • logy hat=o.6935•logx+ 0.9013 • log y hat=0.9013x+0.6935* • log y hat=0.6935x+ 0.9013 • log y hat=0.9013•logx+ 0.6935 8. Use the linear transformation model to predict the number of fish in 12 months. (2 points)
i put a * next to my answers
It is much clearer when you post the complete original post. If you post your answer as part of the question, it will make the question inconsistent. First, do you think it is a linear or exponential relationship?
well i think its linear because when the x values increase so do the y values
JUST KIdding
its an exponential growth lol
exactly! What have you learned about transformation?
not sure, i have taken notes but i lost the notebook earlier yesterday
Do you have a textbook?
no im on online school
You cannot go back to the lessons?
I can but they wont explain everything once i pass the lesson just bits
so i got log y hat=0.9013x+0.6935 as the transformation model out of the answers, but im not sure how to find the number of fish after 12 months, which is confusing me lol
ok, are you looking for the answer or are you looking to understand?
understand please
We'll rewind to the beginning, ok?
ok
Typically, a linear model has the form y=ax+b but that's not our case.
ok
Similarly, an exponential growth model has the form \(y=ax^{bx}\) where a and b are to be found.
so far so good?
yes
However, the parameters a and b are hard to calculate directly from the exponential model. Since we (including you) already know how to model a straight line, we will transform the exponential to a straight line. Then we'd find the parameters as though it is a straight line.|dw:1447097415267:dw| That's where transformation comes in.
@jessicawade are you still there?
yeah my computer wasnt laoding
ohhhh ok :)
The way the transformation works is you would take log (to base 10 in your case) on both sides. Can you do that for me?
Take log on both sides of \(y=ax^{bx}\)
let me try im not very good at math
so on both sides on the y and the ax?
i dont get it xD
@mathmate
\(y=ax^{bx}\) actually should read \(y=a(10)^{bx}\)........ if we take log 10 eventually We'll take log on both sides, so \(log(y)=log(ax^{bx})=log(a)+log(10^{bx})=log(a)+bx~log(10)=bx+log(a)\) This is done by the laws of logarithm (which you'll need to brush up for this course) Put it simply, \(log(y)=bx+log(a)\).........where a and b are constants to be found for the given data set.
So we just finished the transformation part. Except for the laws of logarithm, are you following with the concept?
yeah so far i think haha
It turns out that the constant "a" is the initial value, or the y-intercept.What is the y-intercept in our problem?
is that the same as log y?
|dw:1447098799871:dw| "a", the y-intercept is the value of y when x=0. In our case, a=8 becase the number of fish is 8 at month 0.
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