Answer:
71.123 mph ≤ μ ≤ 77.277 mph
Step-by-step explanation:
Taking into account that the speed of all cars traveling on this highway have a normal distribution and we can only know the mean and the standard deviation of the sample, the confidence interval for the mean is calculated as:
≤ μ ≤ 
Where m is the mean of the sample, s is the standard deviation of the sample, n is the size of the sample, μ is the mean speed of all cars, and 
is the number for t-student distribution where a/2 is the amount of area in one tail and n-1 are the degrees of freedom.
the mean and the standard deviation of the sample are equal to 74.2 and 5.3083 respectively, the size of the sample is 10, the distribution t- student has 9 degrees of freedom and the value of a is 10%.
So, if we replace m by 74.2, s by 5.3083, n by 10 and 
by 1.8331, we get that the 90% confidence interval for the mean speed is:
≤ μ ≤ 
74.2 - 3.077 ≤ μ ≤ 74.2 + 3.077
71.123 ≤ μ ≤ 77.277
The racer take 4 hours (between 8:00 to 12:00) to race 3/4 of 6 miles
3/4 of 6 miles = 18/4 = 4.5 miles
4 hours ⇒ 4.5 miles
1 hour ⇒ 4.5 ÷ 4 = 1.125 miles
The time taken to complete 6 miles = 6 ÷ 1.125 = 16/3 hours = 5.3 hours
<h3>hello!</h3>
Plug in the values of x and solve for y:-
y=5+4x
y=5+4(4)
y=5+16
y=21
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y=5+4x
y=5+5(5)
y=5+20
y=25
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y=5+4x
y=5+4(8)
y=5+32
y=37
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y=5+4x
y=5+4(10)
y=5+40
y=45
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<h3>note:-</h3>
Hope everything is clear; if you need any clarification/explanation, kindly let me know, and I will comment and/or edit my answer :)
Use Pythagorean theorem
a^2 + b^2 = c^2
a = 9, b = x, c = 18
9^2 + x^2 = 18^2
81 + x^2 = 324
x^2 = 243
x = 15.58846
Round to nearest tenth
Solution: x = 15.6
Answer:
420
Step-by-step explanation:
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