121 is big enough to assume normality and not worry about the t distribution. By the 68-95-99.7 rule a 95% confidence interval includes plus or minus two standard deviations. So 95% of the cars will be in the mph range
The question is a bit vague, but it seems we're being asked for the 95% confidence interval on the average of 121 cars. The 121 is a hint of course.
The standard deviation of the average is in general the standard deviation of the individual samples divided by the square root of n:
So repeating our experiment of taking the average 121 cars over and over, we expect 95% of the averages to be in the mph range
That's probably the answer they're looking for.
Answer:
T₆₇ = -413
Step-by-step explanation:
Answer:25
Evan has a summer job to pick berries on a farm.
• He earns
$
2.0$2.00 every
15
15 minutes that he picks strawberries.
• He earns
$
2.40
$2.40 for every
15
15 minutes that he picks blueberries.
• He picked strawberries for an hour and blueberries for
45
45 minutes.
How much money did Evan earn?
Step-by-step explanation:
Answer:
Step-by-step explanation:
The pillow is cylindrical. To determine the amount of fabric needed for the pillow, we would apply the formula for determining the total surface area of a cylinder which is expressed as
Total surface area = 2πr² + 2πrh
Where
r represents the radius of the cylinder.
h represents the height of the cylinder.
π is a constant whose value is 3.14
From the information given,
radius = 5 inches
Height = 18 inches
Therefore,
Area = (2 × 3.14 × 5²) + 2 × 3.14 × 5 × 18
Area = 157 + 565.2 = 722.2
Amount of fabric needed is
722.2 square inches
