You would of taken 28 dollars away after 7 days because if your taking away 4$ each day you just have to figure out 4 times what equals 28 witch is 7
So the answer is 7 days
Arc tan ( 1/√3 ) = arc tan ( √3/3 ) = 30°
180° = π ( in radians )
30° = 180°/6 = π/6
Answer:
Is that you in your pfp?
Step-by-step explanation:
Answer:
Step-by-step explanation:
We would set up the hypothesis test. This is a test of a single population mean since we are dealing with mean
For the null hypothesis,
µ = 12
For the alternative hypothesis,
µ < 12
Since the population standard deviation is given, z score would be determined from the normal distribution table. The formula is
z = (x - µ)/(σ/√n)
Where
x = sample mean
µ = population mean
σ = population standard deviation
n = number of samples
From the information given,
µ = 12 minutes
x = 8 minutes
σ = 12 minutes
n = 36
z = (8 - 12)/(12/√36) = - 4/2 = - 2
Test statistic = - 2
Answer:
Wind speed = 30 mph
Plane speed = 270 mph
Step-by-step explanation:
Given that :
Distance = 600 miles
Let speed of airplane = a ; speed of wind = b
Net speed ; with wind = a + b
Net speed against wind = a - b
Time taken with wind = 2 hours
Time taken against wind = 2.5 hours
Recall :
Speed = distance / time ; distance = speed * time
(a + b) * 2 = (a - b) * 2.5
2a + 2b = 600
a + b = 300 - - - (1)
a = 300 - b
2.5a - 2.5b = 600
a - b = 240 - - - (2)
300 - b - b = 240
300 - 2b = 240
-2b = - 60
b = 30
a = 300 - 30
a = 270
Wind speed = 30 mph
Plane speed = 270 mph
