Answer:
The best point of estimate for the true mean is:

Since the time can't be negative a good approximation for the confidence interval would be (0,5.248) minutes. The interval are tellling to us that at 95% of confidence the average late time is lower than 5.248 minutes.
Step-by-step explanation:
Information given
represent the sample mean for the late time for a flight
population mean
represent the population deviation
n=76 represent the sample size
Confidence interval
The best point of estimate for the true mean is:

The confidence interval for the true mean is given by:
(1)
The Confidence level given is 0.95 or 95%, th significance would be
and
. If we look in the normal distribution a quantile that accumulates 0.025 of the area on each tail we got
Replacing we got:
Since the time can't be negative a good approximation for the confidence interval would be (0,5.248) minutes. The interval are tellling to us that at 95% of confidence the average late time is lower than 5.248 minutes.
Answer:
20 ft long; 12 ft wide
Step-by-step explanation:
Let w = the width of the garden
Then l = w + 8
A = lw
A = (w + 8)w
=====
The sidewalk is 4 ft wide, so, for the big rectangle consisting of garden plus sidewalk:
Width = w +8
Length = w + 16
Area = (w + 8)(w + 16)
=====
The <em>difference</em> between the two areas is the area of the sidewalk (320 ft²).
(w + 8)(w + 16) - (w + 8)w = 320 Factor out w + 8
(w+ 8)(w + 16 – w) = 320 Combine like terms
(w+ 8) × 16 = 320 Divide each side by 16
w + 8 = 20 Subtract 8 from each side
w = 12 ft
l = 12 + 8
l = 20 ft
The garden is 20 ft long by 12 ft wide.
Answer:
you'll go over 2 and then go up 2 to get your 2x and 2y
convert 1/2 to 2/4 <<<<< that is the amount the brothers ate