Answer:
The “E” indicates an arc welding electrode. The first two digits of a 4-digit number and the first three digits of a 5-digit number stand for tensile strength. So, “1” stands for an all position electrode, “2” for a flat and horizontal electrode, and “4” for a flat, horizontal, vertical down and overhead electrode
The total of two whole numbers one after another is 33. for example 10 + 11 (two consecutive integers) = 21
Answer and Step-by-step explanation: The null and alternative hypothesis for this test are:
To test it, use F-test statistics and compare variances of each treatment.
Calculate F-value:
F = 1.8356
The <u>critical value of F</u> is given by a F-distribution table with:
degree of freedom (row): 20 - 1 = 19
degree of freedom (column): 20 - 1 = 19
And a significance level: α = 0.05
= 2.2341
Comparing both values of F:
1.856 < 2.2341
i.e. F-value calculated is less than F-value of the table.
Therefore, failed to reject 
, meaning there is <u>no sufficient data to support the claim</u> that sham treatment have pain reductions which vary more than for those using magnets treatment.
Part a)
The mean height is 69 inches with a standard deviation of 2.5 inches.
If we consider a interval of heights that relies on no more than two standard deviations from the mean, we will cover, approximatelly, 95% of men's heights. Then, we interval that we're looking for is:
Answer: 64 TO 74 INCHES
Part b)
Since [69,74] is half of the interval in the previous answer, we might expect half of 95% as the percentage of men who are in this interval. That is:
Answer: 47.5 PERCENT
Part c)
A interval of heights that relies on no more than one standard deviation from the mean covers, approximatelly, 68% of men's heights. Then, we can consider that the percentage of men that are between 64 and 66.5 inches is given by 47.5 - 68/2 = 13.5.
Answr: 13.5 PERCENT
