Complete question:
The manager of a supermarket would like to determine the amount of time that customers wait in a check-out line. He randomly selects 45 customers and records the amount of time from the moment they stand in the back of a line until the moment the cashier scans their first item. He calculates the mean and standard deviation of this sample to be barx = 4.2 minutes and s = 2.0 minutes. If appropriate, find a 90% confidence interval for the true mean time (in minutes) that customers at this supermarket wait in a check-out line
Answer:
(3.699, 4.701)
Step-by-step explanation:
Given:
Sample size, n = 45
Sample mean, x' = 4.2
Standard deviation = 2.0
Required:
Find a 90% CI for true mean time
First find standard error using the formula:
Standard error = 0.298
Degrees of freedom, df = n - 1 = 45 - 1 = 44
To find t at 90% CI,df = 44:
Level of Significance α= 100% - 90% = 10% = 0.10
Find margin of error using the formula:
M.E = S.E * t
M.E = 0.298 * 1.6802
M.E = 0.500938 ≈ 0.5009
Margin of error = 0.5009
Thus, 90% CI = sample mean ± Margin of error
Lower limit = 4.2 - 0.5009 = 3.699
Upper limit = 4.2 + 0.5009 = 4.7009 ≈ 4.701
Confidence Interval = (3.699, 4.701)
Answer:
$2,700
Step-by-step explanation:
Let the width of the pasture be x, this means that the length of the pasture will be 2x
The area of a rectangle is L * B
Hence,
x * 2x = 18,000
2x^2 = 180,000
x^2 = 90000
x = 300 meters
This means the length is 600 metres
Now, to get the length of the fence, we need to know the actual perimeter which is 2(L + B)
= 2 ( 300 + 600)
2 * 900 = 1,800 metres
The cost is thus 1,800 * $1.50 = $2,700
The answer is -4. The coefficient of a variable is the numerical value directly in front of the variable.
Answer:
52x < $211
Step-by-step explanation:
If Roland uses $289 to purchase the laptop from the $500 that was given to him then he would be left with
500 - 289 = $211
With this he can purchase video games. Since each video game costs the same price of $52 then we can use the variable x to represent the number of games he can buy with the following inequality...
52x < $211
Answer:
Difference between the original and current volumes = 4013140.30 cubic feet
Step-by-step explanation:
Largest pyramid has the square base with one edge = 754 feet
Area of the square base = (Side)²
= (754)²
= 568516 square feet
Volume of the pyramid =
=
= 91152065.3 cubic feet
After erosion,
Area of the base = (745)² = 555025 square feet
Volume of the pyramid =
= 87138925 cubic feet
Difference between the original and current volumes of the pyramid
= 91152065.30 - 87138925
= 4013140.30 cubic feet