Answer:
Step-by-step explanation:
Hello!
Given the variables
X₁: Weight of a safety helmet for racers
X₂: Price of a safety helmet for racers
Note, there is n= 17 observed values for each variable so for all calculations I'll use this number and disregard the 18 mentioned in the text.
a) Scatterplot in attachment.
b) If you look at the diagram it seems that there is a negative linear regression between the price and the weight of the helmets, meaning, the higher the helmet weights, the less it costs.
c) The estimated regression equation is ^Yi= a + bXi
n= 17; ∑Y= 6466; ∑Y²= 3063392; ∑X= 1008; ∑X²= 60294; ∑XY= 367536
Y[bar]= 380.35; X[bar]= 59.29
The estimated regression equation for the price of the helmets as a function of their weight is:
^Yi= 2169.77 -30.18Xi
I hope it helps!
Solution:
Given equation is .
To solve the equation by step by step.
Step 1: Given
Step 2: Combine like terms together.
Plus symbol changed to minus when the term goes from right to left (or) left to right of the equal sign.
Step 3: Subtract the fractions in the left side.
⇒
Step 4: Divide both side of the equation by 3, we get
Hence, the answer is .
The r% of a quantity x is computed by dividing x in 100 parts, and considering r of such parts. So, the r% of the male is
and similarly, the r% of female is
The number of males decreased by this quantity, so now it is
and the number of female increased by this quantity, so now it is
we know that these two new counts are the same number, so we can build and solve the equality
Subtract 20 and add 0.3r from both sides:
Divide both sides by 0.5 to solve for r:
Let's check the answer
The 20% of 30 is , while the 20% of 20 is 4. So, we are stating that
which is true because both expressions evaluate to 24.
