Answer:
Yes, There is significant difference.
Step-by-step explanation:
Null Hypothesis , H0 : Mean income = 15000
Alternate Hypothesis , H1 : Mean income ≠ 15000
t = (x - u) / ( s / √n)
x = sample mean = 14500 here, u = population mean = 15000 here , s = standard deviation = 975 here , n = sample size
t = (14500 - 15000) / (975 / √169)
-500 / 75 = - 6.66
As calculated t value in absolute terms is > 1.96 , ie tabulated value at 95% significance level (two sided). So we reject the null hypothesis in favor of alternate hypothesis. Hence, we state that 'Mean Income ≠ 15000'
C. 5
Step-by-step explanation:
The coeff of

Is 15.
So by that we can write 3m = 15
m is 5.
That's a huge one. I don't think that anyone will actually answer that.
Start by finding the area of one of the stools with this formula:
A=(3.14)(12)(12)
Then multiply that answer by five, since there are 5 stools.
Hope this helps :) good luck