Answer:
S₁₅ = 645
Step-by-step explanation:
The sum to n terms of an arithmetic sequence is
=
[ 2a₁ + (n - 1)d ]
where a₁ is the first term and d the common difference
Using the nth term formula
= 5n + 3 , then
a₁ = 5(1) + 3 = 5 + 3 = 8
a₂ = 5(2) + 3 = 10 + 3 = 13 , then
d = a₂ - a₁ = 13 - 8 = 5
Thus
S₁₅ =
[ (2 × 8) + (14 × 5) ]
= 7.5( 16 + 70)
= 7.5 × 86
= 645
Answer:
The predicted life expectancy of men in a country in which the life expectancy of women is 70 years is 65.33 years.
Step-by-step explanation:
The least square regression line is used to predict the value of the dependent variable from an independent variable.
The general form of a least square regression line is:

Here,
<em>y</em> = dependent variable
<em>x</em> = independent variable
<em>α</em> = intercept
<em>β</em> = slope
The regression line to predict the life expectancy of men in a country from the life expectancy of women in that country is:

Compute the life expectancy of men in a country in which the life expectancy of women is 70 years as follows:


Thus, the predicted life expectancy of men in a country in which the life expectancy of women is 70 years is 65.33 years.
Answer:
3
Step-by-step explanation:
The norm of a vector
is equal to the square root of the inner product of
with itself.
a. 
b. 