Answer:
B The cost to use the service for one month if zero songs are downloaded
Let be the random variable for the number of marks a given student receives on the exam.
10% of students obtain more than 75 marks, so
where follows a standard normal distribution. The critical value for an upper-tail probability of 10% is
where denotes the CDF of , and denotes the inverse CDF. We have
Similarly, because 20% of students obtain less than 40 marks, we have
so that
Then are such that
and we find
Answer:
6.25
Step-by-step explanation:
Equation of circle is (x - a)^2 + (y - b)^2 = r^2; where (a, b) is the center and r is the radius.
r^2 = (2 - 3)^2 + (-1 - 4)^2 = (-1)^2 + (-5)^2 = 1 + 25 = 26
Equation is (x - 2)^2 + (y + 1)^2 = 26
Answer:
The equation of the line is y = x + 2
Step-by-step explanation:
The form of the equation that passes through two points (x1, y1) and (x2, y2) is y = m x + b, where
- m is the slope of the line whose rule is
- b is the y-intercept, you can find it by substituting x, y in the equation by (x1, y1) OR (x2, y2)
Let us solve the question:
∵ The line passes through the points (-3, -2) and (3, 6)
∴ x1 = -3 and x2 = 3
∴ y1 = -2 and y2 = 6
→ Use the rule of m to find it
∵
→ Simplify it by dividing up and down by 2
∴ m =
→ Substitute its value in the form of the equation above
∴ y = x + b
→ To find b substitute x and y by x1 and y1
∴ -2 = (-3) + b
∴ -2 = -4 + b
→ Add 4 to both sides
∴ -2 + 4 = -4 + 4 + b
∴ 2 = b
→ Substitute it in the form of the equation
∴ y = x + 2
∴ The equation of the line is y = x + 2