Answer:
The answer is below
Step-by-step explanation:
From the table, the mean (μ) = 1390.75 and the standard deviation (σ) = 518.75
The confidence level (C) = 90% = 0.9
α = 1 - C = 1 - 0.9 = 0.1
α/2 = 0.1 / 2 = 0.05
The z score of α/2 (0.05) is the same as the z score of 0.45 (0.5 - 0.05) which is equal to 1.645.
The margin of error (E) is given as:

The confidence interval = μ ± E = 1390.75 ± 228.07 = (1162.68, 1618.82)
The confidence interval is between 1162.68 and 1618.82.
Answer:
rate of change = 1.5 dollars per mile
Step-by-step explanation:
cost for travelling 1 mile = 3.75
cost 2 miles = 5.25
cost 3 miles = 6.75
cost 4 miles = 8.25
The equation would just be x=8 since the x of both points is 8.
Let a,b,c,d and e are five numbers
mean = (a +b+ c+ d+e)/5 = 30
⇒ (a +b+ c+ d+e) = 150_______(1)
now, Let the number excluded be a
then, new mean = (b+ c+ d+e)/4 = 28
⇒ (b+ c+ d+e)= 112
putting this value in (1),
⇒a + 112 = 150
⇒a = 150 -112 = 38
excluded number = 38
-converting to a common denominator
The terms -c of the left side was converted to -4ac/4a to have the same denominator of b^2/4a.