complete question:
A ship traveled for a total of 85 miles over the course of 5 hours. Heading west, the ship traveled at an average speed of 14 miles per hour, and heading north, it traveled at an average speed of 19 miles per hour. For how many hours was the ship heading north?
Answer:
The ship heading north traveled for 3 hours
Step-by-step explanation:
A ship travels for a total of 85 miles over the course of 5 hours journey. The speed of the journey can be calculated below.
speed = distance/time
total distance = 85
total time = 5 hours
speed = 85/5
speed = 17 miles/hr
West direction
Heading west the ship traveled at an average speed of 14 miles per hour. The speed can be represented for this journey as follows.
speed = distance/time
14 = dist/time
let
a = time traveled west
distance = 14a
North direction
speed = dist/time
19 = dist/time
time travel north = 5 - a
distance = 19(5 - a)
distance = 95 - 19a
Total distance traveled = 85 miles
85 = 14a + 95 - 19a
85 = -5a + 95
-10 = -5a
a = -10/-5
a = 2
The ship heading north will travel for 5 - 2 = 3 hours
Addends are any of the numbers added together in an equation.
The only time their grouping would matter would be if there were parentheses used to alter the normal Order of Operations.
For ex:
2 - (8 + 3) here, the 8 and 3 have to be grouped together before doing the subtraction.
Any addition problem without parentheses can be used for one where the grouping doesn't matter
Answer:
a) Null hypothesis:
Alternative hypothesis:
b) 
(1)
Replacing we got:
The p value for this case would be given by:
c) For this case we see that the p value is higher than the significance level of 0.05 so then we have enough evidence to FAIL to reject the null hypothesis and we can't conclude that the true proportion workers belonged to unions is significantly higher than 11.3%
Step-by-step explanation:
Information given
n=400 represent the random sample taken
X=52 represent the workers belonged to unions
estimated proportion of workers belonged to unions
is the value that we want to test
represent the significance level
Confidence=95% or 0.95
z would represent the statistic
represent the p value
Part a
We want to test if the true proportion of interest is higher than 0.113 so then the system of hypothesis are.:
Null hypothesis:
Alternative hypothesis:
Part b
The statistic is given by:
(1)
Replacing we got:
The p value for this case would be given by:
Part c
For this case we see that the p value is higher than the significance level of 0.05 so then we have enough evidence to FAIL to reject the null hypothesis and we can't conclude that the true proportion workers belonged to unions is significantly higher than 11.3%
If you expand out the brackets you get this,
(4+5i)(a+2i) = 4a + (5a)i + 8i - 10
The -10 comes from 5i * 2i.
Squaring i becomes -1.
Let's group the real stuff together,
and imaginary separately,
(4a - 10) + (5a + 8)i
For this to be purely imaginary,
the real part needs to be zero.
Therefore 4a - 10 = 0
Solve for a.
