We'll use Cramer's rule for 2 equations:
ax + by = e
cx + dy = f
5x -3y = 18 a=5 b=-3 e=18
2x + 7y = -1 c=2 d=7 f=-1
denominator determinant (dn) = (a * d) - (c * b) = 5 * 7 - (2 * -3) = 41
x = [(e * d) - (f * b)] / dn
[18 * 7 - (-1 * -3)] / 41 =
123 / 41 = 3
y = [(a * f) - (c * e)] / dn
= (5 * -1) -(2 * 18) / 41 =
-41 / 41 = -1
Source:
1728.com/cramer.htm
Answer:
3/8, 2/5, 11/20, 23/40, 7/10, 3/4
Step-by-step explanation:
Just change them all to the same denominator and you're good. Put all of the fractions' denominators to 40 as that's the least common denominator. 3/4 turns into 30/40. 2/5 turns into 16/40. 3/8 turns into 15/40. 7/10 turns into 28/40. 11/20 turns into 22/40. And 23/40 stays as it is, because the denominator is already 40.
Putting them in order is now simple,
3/8 (15/40) < 2/5 (16/40) < 11/20 (22/40) < 23/40 < 7/10 (28/40) < 3/4 (30/40)
***When you multiply any fraction to change its denominator, multiply it by the same thing to the numerator as well.
Good Luck!
100 cm = 1 meter
80 cm = 0.8 meter
200 meters/.8 meters = number of boards
250
Answer:
Option C.
Step-by-step explanation:
Sampling bias is a problem during the initial data gathering step of a survey.
When the first step is wrong, then the survey cannot produce non biased results.
The problem occurs when the design of the study is wrong the data collection procedure is wrong.
So, here answer seems C, because the starting point is not selected at random in this survey.
(C) Jean wants to estimate the mean amount of money spent on clothes per week by mall shoppers. She collects data from every 10th person entering a clothing store at the mall.
