Answer:
Step-by-step explanation:
The ship sails at 20 km / h.
So
20 km / h x 2 h = 40 km
The boat moves 40 km to the northeast.
Then, in the same way:
20 km / h x 1 h = 20 km.
The ship moves 20 km northwest.
We solve this problem using vectors. In this case, we must perform the sum of two vectors a and b
a) magnitude = 40 km and direction 20 degrees east
b) magnitude = 20 km and direction 10 degrees northwest
In Cartesian coordinates, these vectors are written as:
a) 40sin (20º) i + 40cos (20º) j = 13,68i + 37,59j
b) -20sin (10th) i + 20cos (10th) j = -3,473i + 19,70j
The displacement vector of the ship would be the sum of a + b
a + b = 10,207i + 57,29j Finally, the magnitude of the a + b vector will tell us how far the ship is
√(10.21² + 57.29²) = 58.92km
The cost of each Piano Lesson = $30
If there are x lessons, the total cost of lessons can be expressed as 30x.
Since the number of lessons cannot be negative, the value of x can be 0 or greater than 0, where x=0 shows no lesson.
For 1 lesson, x = 1
So the cost will be = 30(1) = $30
In ordered pair we can write it as (1, 30)
If we consider there is an option to attend half portion of a lecture, then for 1 and half lectures, x = 1.5
So, the cost for 1.5 lectures will be = 30(1.5) = $45
In ordered pair we can write it as (1.5, 45)
For 3 lesson, x = 3
The cost of 3 lessons will be = $90
In ordered pair we can write this as (3, 90)
So, from the given options, only following 2 ordered pairs satisfy the given conditions:
1) (1,30)
2) (3, 90)
Answer:
A sample of 601 bricks will be needed.
Step-by-step explanation:
In a sample with a number n of people surveyed with a probability of a success of , and a confidence level of , we have the following confidence interval of proportions.
In which
z is the zscore that has a pvalue of .
The margin of error is:
95% confidence level
So , z is the value of Z that has a pvalue of , so .
How large a sample will we need?
A sample of n bricks will be needed.
n is found when M = 0.04.
We have no estimate for the proportion of defective bricks, so we work with the worst case scenario, which is
Rounding up
A sample of 601 bricks will be needed.
Answer:
495 students are at Lincoln Middle School
Step-by-step explanation:
450/?
450 = 90%
450*90% = 450 * 0.90 = 405
450- 405 = 45
450+45 = 495