Sovi.AI - AI Math Tutor

Scan to solve math questions

QUESTION IMAGE

listed below are numbers of internet users per 100 people and numbers o…

Question

listed below are numbers of internet users per 100 people and numbers of scientific award winners per 10 million people for different countries. construct a scatterplot, find the linear correlation coefficient r, and find the p - value of r. determine whether there is sufficient evidence to support a claim of linear correlation between the two variables. use significance level of α = 0.01.
internet users | 79.9 80.4 57.7 66.4 78.3 38.4
award winners | 5.3 9.1 3.3 1.8 10.5 0.1
construct a scatterplot. choose the correct graph below
a.
b.
c.
d.
the linear correlation coefficient is r = \boxed{}.
(round to three decimal places as needed.)

Explanation:

Step1: Identify Variables

Let \( x \) be Internet Users (per 100 people): \( [79.9, 80.4, 57.7, 66.4, 78.3, 38.4] \)
Let \( y \) be Award Winners (per 10 million people): \( [5.3, 9.1, 3.3, 1.8, 10.5, 0.1] \)

Step2: Calculate Necessary Sums

  • \( n = 6 \)
  • \( \sum x = 79.9 + 80.4 + 57.7 + 66.4 + 78.3 + 38.4 = 401.1 \)
  • \( \sum y = 5.3 + 9.1 + 3.3 + 1.8 + 10.5 + 0.1 = 30.1 \)
  • \( \sum xy = (79.9×5.3) + (80.4×9.1) + (57.7×3.3) + (66.4×1.8) + (78.3×10.5) + (38.4×0.1) \)

\( = 423.47 + 731.64 + 190.41 + 119.52 + 822.15 + 3.84 = 2291.03 \)

  • \( \sum x^2 = 79.9^2 + 80.4^2 + 57.7^2 + 66.4^2 + 78.3^2 + 38.4^2 \)

\( = 6384.01 + 6464.16 + 3329.29 + 4408.96 + 6130.89 + 1474.56 = 28191.87 \)

  • \( \sum y^2 = 5.3^2 + 9.1^2 + 3.3^2 + 1.8^2 + 10.5^2 + 0.1^2 \)

\( = 28.09 + 82.81 + 10.89 + 3.24 + 110.25 + 0.01 = 235.29 \)

Step3: Apply Correlation Formula

The formula for \( r \) is:

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

Substitute values:

  • Numerator: \( 6×2291.03 - 401.1×30.1 = 13746.18 - 12073.11 = 1673.07 \)
  • Denominator part 1: \( 6×28191.87 - (401.1)^2 = 169151.22 - 160881.21 = 8270.01 \)
  • Denominator part 2: \( 6×235.29 - (30.1)^2 = 1411.74 - 906.01 = 505.73 \)
  • Denominator: \( \sqrt{8270.01×505.73} \approx \sqrt{4182490.6573} \approx 2045.11 \)
  • \( r = \frac{1673.07}{2045.11} \approx 0.818 \)

Answer:

\( 0.818 \)