1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
solniwko [45]
3 years ago
9

At a recent county fair, you observed that at one stand people's weight was forecasted, and were surprised by the accuracy (with

in a range). Thinking about how the person could have predicted your weight fairly accurately (despite the fact that she did not know about your "heavy bones"), you think about how this could have been accomplished. You remember that medical charts for children contain 5%, 25%, 50%, 75% and 95% lines for a weight/height relationship and decide to conduct an experiment with 110 of your peers. You collect the data and calculate the following sums: where the height is measured in inches and weight in pounds.
(a) Calculate the slope and intercept of the regression.
(b) Find the regression R2.
Mathematics
1 answer:
MatroZZZ [7]3 years ago
6 0

Answer:

a)Slope: \hat \beta_1 =\frac{7625.9}{1248.9}=6.106

Intercept: \hat \beta_o = 157.955 -6.106 (69.686)=-267.548

b) r=\frac{7625.9}{\sqrt{[1248.9][94228.8]}}=0.657  

And the determination coeffecient is r^2 = 0.657^2 =0.432  

Step-by-step explanation:

Data given and definitions

The correlation coefficient is a "statistical measure that calculates the strength of the relationship between the relative movements of two variables". It's denoted by r and its always between -1 and 1.  

The sum of squares "is the sum of the square of variation, where variation is defined as the spread between each individual value and the grand mean"    

When we conduct a multiple regression we want to know about the relationship between several independent or predictor variables and a dependent or criterion variable.  

n=110, \sum x_i y_i = \sum (X-\bar X)(Y-\bar Y) =7625.9,\sum x^2_i=\sum (x-\bar x)^2 =1248.9 , sum y^2_i=\sum(y-\bar y)^2 =94228.8  

\sum Y_i =17375 , \sum X_i = 7665.5

Part a

The slope is given by this formula:

\hat \beta_1 =\frac{\sum (x-\bar x) (y-\bar y)}{\sum (x-\bar x )^2}

If we replace we got:

\hat \beta_1 =\frac{7625.9}{1248.9}=6.106

We can find the intercept with the following formula

\hat \beta_o = \bar y -\hat \beta_1 \bar x

We can find the average for x and y like this:

\bar X=7665.5/110 =69.686, \bar y= 17375/110=157.955

And replacing we got:

\hat \beta_o = 157.955 -6.106 (69.686)=-267.548

Part b

In order to calculate the correlation coefficient we can use this formula:  

r=\frac{\sum (x-\bar x)(y-\bar y) }{\sqrt{[\sum (x-\bar x)^2][\sum(y-\bar y)^2]}}  

For our case we have this:  

n=110, \sum x_i y_i = \sum (X-\bar X)(Y-\bar Y) =7625.9,\sum x^2_i=\sum (x-\bar x)^2 =1248.9 , sum y^2_i=\sum(y-\bar y)^2 =94228.8  

So we can find the correlation coefficient replacing like this:

r=\frac{7625.9}{\sqrt{[1248.9][94228.8]}}=0.657  

And the determination coeffecient is r^2 = 0.657^2 =0.432  

You might be interested in
Rebecca has 3 pairs of running shoes.She bought new shoelaces for each pair.How many shoelaces did she buy?
kvasek [131]

Answer: 6 shoelaces

Step-by-step explanation:

Since 1 pair of shoes has 2 shoelaces, 3 x 2 = 6

3 pairs x 2 shoelaces = 6 shoelaces

Hope this helped!

P.S. PLS give brailiest! I only have one brainliest!!

4 0
3 years ago
Read 2 more answers
Write an equation for the quadratic graphed below: x-intercepts: (-1,0) and (4,0); y-intercept: (0,1)
Luda [366]

Answer:

y = (1/4)x² - (5/4)x + 1

Step-by-step explanation:

The x-intercepts of the quadratic equation are simply it's roots.

Thus, we have;

(x + 1) = 0 and (x - 4) = 0

Now, formula for quadratic equation is;

y = ax² + bx + c

Where c is the y intercept.

At y-intercept: (0,1), we have;

At (-1,0), thus;

0 = a(1²) + b(1) + 1

a + b = -1 - - - (1)

At (4,0), thus;

0 = a(4²) + b(4) + 1

16a + 4b = -1

Divide both sides by 4 to get;

4a + b = -1/4 - - - (2)

From eq 1, b = -1 - a

Thus;

4a + (-1 - a) = -1/4

4a - 1 - a = -1/4

3a - 1 = -1/4

3a = 1 - 1/4

3a = 3/4

a = 1/4

b = -1 - 1/4

b = -5/4

Thus;

y = (1/4)x² - (5/4)x + 1

6 0
2 years ago
5. While working out, Susie doos 25 sit-ups for every 12 push-ups. If she does 00 push-ups, how
Norma-Jean [14]
2500 is the answer ...
3 0
3 years ago
Which expression shows the result of applying the distributive property to 9(2+5m) ?
vovikov84 [41]

Answer:

<h2>18 + 45m</h2>

Step-by-step explanation:

The distributive property: a(b + c) = ab + ac

9(2 + 5m) = (9)(2) + (9)(5m) = 18 + 45m

3 0
2 years ago
Which expression is equivalent to that
kari74 [83]

Answer:

3. 9x

4. D. -5v + 4

Step-by-step explanation:

3. (-3+12)v

= 9v

4. Combine like terms:

(-2v - 3v) + (8 - 4)

= -5v + 4

6 0
3 years ago
Read 2 more answers
Other questions:
  • Yoko made 4 identical necklaces, each having beads and a pendant. The total cost of the beads and pendants for all 4 necklaces w
    13·2 answers
  • What are the coordinates of the vertex of the table? Is it a minimum or a maximum?
    10·1 answer
  • Which only lists multiples of 16?
    15·2 answers
  • Divide 3 by 8, then multiply z by the result
    11·1 answer
  • A polling company surveyed 5000 registered voters about which candidate they support in the upcoming election. The results of th
    7·1 answer
  • I need this I really really do
    13·1 answer
  • A cyclist leaves his training base for a morning workout, riding at the rate of 12 mph. One hour later, her support staff leaves
    7·1 answer
  • Can someone please solve this please.
    11·1 answer
  • Insert the missing number<br> 37 16 35
    6·1 answer
  • SOMEONE PLS HELP ME ASAP ON THESE QUESTIONS!!!!!!!
    9·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!