Answer:
The critical value is T = 1.895.
The 90% confidence interval for the mean repair cost for the washers is between $48.159 and $72.761
Step-by-step explanation:
We have the standard deviation for the sample, so we use the t-distribution.
The first step to solve this problem is finding how many degrees of freedom, we have. This is the sample size subtracted by 1. So
df = 8 - 1 = 6
90% confidence interval
Now, we have to find a value of T, which is found looking at the t table, with 6 degrees of freedom(y-axis) and a confidence level of 
. So we have T = 1.895, which is the critical value.
The margin of error is:
In which s is the standard deviation of the sample and n is the size of the sample.
The lower end of the interval is the sample mean subtracted by M. So it is 60.46 - 12.301 = $48.159
The upper end of the interval is the sample mean added to M. So it is 60.46 + 12.301 = $72.761
The 90% confidence interval for the mean repair cost for the washers is between $48.159 and $72.761
I’m pretty sure it’s 65% please correct me if i’m wrong :)
Answer:
1240.4 mm²
Step-by-step explanation:
SA of Pentagonal pyramid:
(as)(5/2) + (sl)(5/2)
↑ ↑
base area lateral area
_____________________
a: apothem (in-radius) length, s: side length.
l: slant height.
______________________
Since we are already given the base area which is 440.4 mm². All we need to do is find the lateral area and add both areas together.
Given that the triangular face of the lateral part has a side/base length of 16mm, and a 20mm slant height.
A triangle has an area of ½bh and since there are 5 of these faces total, (5)(½bh) = (5/2)(bh). In a three dimensional perspective, b will be s and h will be l so (sl)(5/2).
With this information the surface area is:
(16)(20)(5/2)mm + (440.4 mm²) →
800 mm² + 440.4 mm² =
1240.4 mm²
Answer:
4 m/s downwards
Step-by-step explanation:
Velocity is given by dividing the distance by time taken to cover the diatance. Therefore, expressed as v=d/t
The distance is given as 24 m but the time given covers only half the distance. Therefore, the distance is 0.5*21=12 m
Time taken is given as 3 s
Substituting 12 m for d and 3 s for t then
V=12/3= 4 m/s
Velocity must have direction component hence velocity is 4 m/s downwards
Answer:
75.27
Step-by-step explanation:
Subtract this week from last week
289-213.73
75.27
