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Answer:
15 miles per hour is the speed of the slower train.
Step-by-step explanation:
As given in the figure attached,
Let the speed of train 1 is v and train 2 is u.
Therefore, distance traveled in 2 hours by train 1 will be = 2v miles
and distance traveled by train 2 will be = 2u miles
Now we can see in the figure a right angle triangle is formed by the two trains.
AB² + BC² = AC²
(2v)² + (2u)²= (65.30)²
4v² + 4u² = 4264.09
Now we divide this equation by 4
v² + u² = 1066.02
If speed of the slower train is v miles per hour then as per statement of the question.
u = v - 14
v = u + 14
By putting the value of v in the equation
(u + 14)² + u² = 1066
u² + 196 + 28u + u² = 1066
2u² + 28u + 196 = 1066
2u² + 28u + 196 - 1066 = 0
2u² + 28u - 870 = 0
By diving this equation by 2
u² + 14u - 435 = 0
u² + 29u - 15u - 435 = 0
u(u + 29) - 15(u + 29) = 0
(u + 29)(u - 15) = 0
u = -29, 15
Since speed can not be with negative notation so u = 15 miles per hour will be the speed.
Therefore, 15 miles per hour is the speed of the slower train.
Answer:
The 95% confidence interval for the population mean rating is (5.73, 6.95).
Step-by-step explanation:
We start by calculating the mean and standard deviation of the sample:
We have to calculate a 95% confidence interval for the mean.
The population standard deviation is not known, so we have to estimate it from the sample standard deviation and use a t-students distribution to calculate the critical value.
The sample mean is M=6.34.
The sample size is N=50.
When σ is not known, s divided by the square root of N is used as an estimate of σM:
The degrees of freedom for this sample size are:
The t-value for a 95% confidence interval and 49 degrees of freedom is t=2.01.
The margin of error (MOE) can be calculated as:
Then, the lower and upper bounds of the confidence interval are:
The 95% confidence interval for the mean is (5.73, 6.95).