Answer:
x = 0
Step-by-step explanation:
if 2y + x = 4
we can assume that y = 2
if y - 3x = 2
it means 2 - 0 = 2
therefore x = 0
Answer:
59 to 66
Step-by-step explanation:
Mean test scores = u = 74.2
Standard Deviation =
= 9.6
According to the given data, following is the range of grades:
Grade A: 85% to 100%
Grade B: 55% to 85%
Grade C: 19% to 55%
Grade D: 6% to 19%
Grade F: 0% to 6%
So, the grade D will be given to the students from 6% to 19% scores. We can convert these percentages to numerical limits using the z scores. First we need to to identify the corresponding z scores of these limits.
6% to 19% in decimal form would be 0.06 to 0.19. Corresponding z score for 0.06 is -1.56 and that for 0.19 is -0.88 (From the z table)
The formula for z score is:

For z = -1.56, we get:

For z = -0.88, we get:

Therefore, a numerical limits for a D grade would be from 59 to 66 (rounded to nearest whole numbers)
Urn 1 = 4 green balls and 6 blue balls, a total of 10 balls
Urn 2 = 6 green balls and 2 blue balls, a total of 8 balls.
Probability of blue balls:
Urn 1 : P = 6/10
Urn 2 : P = 2/8
Probability that both balls are blue:
6/10 * 2/8 = 6*2 / 10*8 = 12/80 = 6/40 = 3/20
Answer is B. 3/20
Answer:B
Step-by-step explanation: