Line 1 and Line 4 are parallel lines
Solution:
General equation of a line:
y = mx + c
where m is the slope and c is the y-intercept of the line.
<u>To find the slope of each line:</u>
Line 1:
Slope
Line 2:
Add 7 on both sides, we get
Slope
Line 3:
Slope
Line 4:
Subtract x from both sides, we get
Multiply by on both sides, we get
Slope
<em>Two lines are parallel, if their slopes are equal.</em>
From the above slopes,
Therefore Line 1 and Line 4 are parallel lines.
Answer:
21
Step-by-step explanation:
Using<em> Simple Random Sampling</em>, we can estimate the sample size by the formula
where
n = sample size
Z = the z-score corresponding to the confidence level 99.5%
S = the assumed standard deviation = 3 seconds
e = margin of error = 2 seconds
<em>It is worth noticing that the higher the confidence level, the larger the sample should be. </em>
The z-score corresponding to a confidence level of 99.5% can be obtained either with a table or the computer and equals
Z = 3.023
Replacing the values in our formula
So the size of the sample should be at least 21.
Answer:
arc length = 4π units
Step-by-step explanation:
The arc length is calculated as
arc = circumference of circle × fraction of circle
= 2πr ×
= 2π × 8 ×
= 2π × 2
= 4π units ← exact answer