Answer:
y=0.25x+35
Step-by-step explanation:
if the truck doesn't have to travel at all, it costs $35 for the loading fee, so the y-intercept is (0, 35). As x increases by 1, y increases by 0.25, so the slope is 0.25. Therefore, the equation is y=0.25x+35
Answer:
y = - 9
Step-by-step explanation:
The equation of a line in slope- intercept form is
y = mx + c ( m is the slope and c the y- intercept )
Calculate m using the slope formula
m = (y₂ - y₁ ) / (x₂ - x₁ )
with (x₁, y₁ ) = (1, - 6) and (x₂, y₂ ) = (4, 3)
m = 
= 
= 3
y = 3x + c ← is the partial equation
To find c substitute any of the 2 points into the partial equation
Using (4, 3), then
3 = 12 + c ⇒ c = 3 - 12 = - 9, hence
y- intercept c = - 9 ⇒ (0, - 9 )
Answer:
The scores are between 50 and 90
Step-by-step explanation:
When we say middle 95%, we means that this value falls between 2 standard deviations of the mean i.e
μ ± 2σ
Hence,
mean of 70 and a standard deviation of 10
μ ± 2σ
μ - 2σ
70 - (2 × 10)
= 70 - 20
= 50
μ + 2σ
= 70 + (2 × 10)
= 70 + 20
= 90
a. Find the probability that an individual distance is
greater than 214.30 cm
We find for the value of z score using the formula:
z = (x – u) / s
z = (214.30 – 205) / 8.3
z = 1.12
Since we are looking for x > 214.30 cm, we use the
right tailed test to find for P at z = 1.12 from the tables:
P = 0.1314
b. Find the probability that the mean for 20 randomly
selected distances is greater than 202.80 cm
We find for the value of z score using the formula:
z = (x – u) / s
z = (202.80 – 205) / 8.3
z = -0.265
Since we are looking for x > 202.80 cm, we use the
right tailed test to find for P at z = -0.265 from the tables:
P = 0.6045
c. Why can the normal distribution be used in part (b),
even though the sample size does not exceed 30?
I believe this is because we are given the population
standard deviation sigma rather than the sample standard deviation. So we can
use the z test.
