Answer: The answer is 314.28 cm² (approx.).
Step-by-step explanation: Given that an engineer is going to install a new water pipe. The diameter of this circular pipe is, d = 20 cm.
We need to find the area 'A' of the circular cross-section of the pipe.
Given, diameter of the circular section is
So, the radius of the circular cross-section will be
Therefore, cross-sectional area of the pipe is
Thus, the answer is 314.28 cm² (approx.).
Answer:
1. <em>L = 3D +59</em>
2. 158 miles
Step-by-step explanation:
For the second part:
Since each day 3 miles of the road is being added, we can simply multiply the number 33 by 3, getting 99. If the road started with 59 miles, we need to add 59 to 99, getting 158 miles.
Explanation:
The triangle is right angled.
The formula for area of the triangle:
base = 3
height = 4
substitute the values:
The sum of all the measurements is just the average times the number.
So if the average of all 92 is 7 the sum of those is
The average of the last two is 7.2 so their sum is
That means the sum of the first 90 is
so the average of the first 90 is
cm
Answer:
One can be 95% confident that the drive-through service times of fast-food chain is between 169 seconds and 172 seconds.
Step-by-step explanation:
The confidence interval gives a range of value for the population mean or parameter, which is calculated from the statistic value of the data (that is sample statistic). This range gives the interval which is associated with a certain level of confidence for which the interval will contain the true value of the unknown parameter (true value). In the scenario above, the associated confidence level is 95%.Hence, we can be 95% confident that the true value will be continued with the interval (169 ; 172)