Answer:
Step-by-step explanation:
Confidence interval for the difference in the two proportions is written as
Difference in sample proportions ± margin of error
Sample proportion, p= x/n
Where x = number of success
n = number of samples
For the men,
x = 318
n1 = 520
p1 = 318/520 = 0.61
For the women
x = 379
n2 = 460
p2 = 379/460 = 0.82
Margin of error = z√[p1(1 - p1)/n1 + p2(1 - p2)/n2]
To determine the z score, we subtract the confidence level from 100% to get α
α = 1 - 0.95 = 0.05
α/2 = 0.05/2 = 0.025
This is the area in each tail. Since we want the area in the middle, it becomes
1 - 0.025 = 0.975
The z score corresponding to the area on the z table is 1.96. Thus, confidence level of 95% is 1.96
Margin of error = 1.96 × √[0.61(1 - 0.61)/520 + 0.82(1 - 0.82)/460]
= 1.96 × √0.0004575 + 0.00032086957)
= 0.055
Confidence interval = 0.61 - 0.82 ± 0.055
= - 0.21 ± 0.055
ok what do u need help with I don't see anything
Answer: Approximately 4.7 hours.
Step-by-step explanation:
He rode the bicycle for some time before it broke down and he walked the remaining distance. This means that Jim covered a total of 165 miles by riding at a speed of 35 miles per hour and walking at a speed of 3 miles per hour.
Let x = the distance covered by riding the bicycle.
Let y = the distance covered by walking.
Time = distance /speed
Time he used in riding would be x/35
Time he used in walking would be y/3
Since the entire trip took 7 hours,
x/35 + y/3 = 7
3x + 35y = 735 - - - - - - - - 1
Total miles covered is 165. Therefore,
x + y = 165 - - - - - - - - -- - -2
Substituting x = 165-y into equation 1, it becomes
3(165-y) + 35y = 735
495-3y + 35y = 735
-3y + 135y = 735-495
132y = 240
y = 240/132
y = 1.81m
x = 165 - 1.81 = 163.19
Amount of time that he spent on the bicycle will be
x/35 = 163.19/35
= 4.66
Approximately 4.7 hours.
The correct answer is D because you already have one side and one angle that are equal so you need one more side
