The equation for the horizontal line is
y=3
So if Angela entered the same restaurant 4 times, we have 4 "instances" of her entering the restaurant.
Each instance, she ordered a salad. The price of this salad is unknown, so we'll say the price is "S".
Each instance, she payed a $5 tip.
So we have 4 instances of spending S, and 4 instances of spending 5.
We know this totals 54.
Knowing all of this information, we can write our equation like this:
4(S + 5) = 54
Divide
S + 5 = 13.50
Subtract
S = 8.50
The cost of salad is $8.50
Answer:
Margin of Error = 5.4088 ;
Confidence interval = (30.1 ; 40.9)
Interval estimate are almost the same
Step-by-step explanation:
Given that :
Population standard deviation, σ = 9.3
Sample size, n = 8
Xbar = 35.5
Confidence level = 90%
The confidence interval:
Xbar ± Margin of error
Margin of Error = Zcritical * σ/sqrt(n)
Zcritical at 90% = 1.645
Margin of Error = 1.645 * 9.3/sqrt(8) = 5.4088
Confidence interval :
Xbar ± Margin of error
35.5 ± 5.4088
Lower boundary = (35.5 - 5.4088) = 30.0912 = 30.1
Upper boundary = (35.5 + 5.4088) = 40.9088 = 40.9
(30.1 ; 40.9)
T distribution =. (30.5 ; 40.5)
Normal distribution = (30.1, 40.9)
