Answer:
0.621
Step-by-step explanation:
Number of people that have run a red light in the last year = 290
Number of people that have not run a red light in the last year = 177
Total number of respondents = 290 + 177
= 467
Pr(if a person is chosen at random, they have run a red light in the last year) =
=
= 0.621
The probability that if a person is chosen at random, they have run a red light in the last year is 0.621.
Answer: 30
Step-by-step explanation:
If we were to draw diagonal BD, then we would create two congruent triangles, and we could find the area of each using the formula .
However, since there are two triangles, we can double this, giving us .
So, the area is
Answer:
a) Figure attached
b)
c) The correlation coefficient would be r =0.47719
d)
Step-by-step explanation:
(a) Draw a scatter diagram for the data.
See the figure attached
(b) Find x, y, b, and the equation of the least-squares line. (Round your answers to three decimal places.) x =__ y =__ b =__ y =__ + __x
Where:
With these we can find the sums:
And the slope would be:
Nowe we can find the means for x and y like this:
And we can find the intercept using this:
So the line would be given by:
(c) Find the sample correlation coefficient r and the coefficient of determination r?2. (Round your answers to three decimal places.)
n=14
And in order to calculate the correlation coefficient we can use this formula:
So then the correlation coefficient would be r =0.47719
What percentage of variation in y is explained by the least-squares model? (Round your answer to one decimal place.)
The % of variation is given by the determination coefficient given by and on this case
, so then the % of variation explaines is 22.8%.
(d) If a female baby weighs 21 pounds at 1 year, what do you predict she will weigh at 30 years of age? (Round your answer to two decimal places.) ___ lb
So we can replace in the linear model like this:
