Answer:
95% confidence interval for the population mean is 20.255 and 17.945
Step-by-step explanation:
given data
mean = 19.1
standard deviation = 1.5
n = 9
to find out
95% confidence interval for the population mean
solution
we know 95% confidence interval formula i.e.
mean +/- t * standard deviation/
.............1
here t for 9 students 2.31 ( from t table)
so put all value n t standard deviation and mean in equation 1
= mean +/- t * standard deviation/
= 19.1 +/- 2.31 * 1.5/
= 19.1 +/- 2.31 * 1.5/
= 20.255 and 17.945
95% confidence interval for the population mean is 20.255 and 17.945
There are 2 unknown terms in this problem
the amount of cement the first team received is termed as 'x' hereafter
the cement the second team received is termed as 'y'
the first team received 50 kg less, the 1st equation is as follows;
x = y - 50 after rearranging
1) x-y = -50
for every hour 150 kg and 200 kg were used by the two teams separately
after three hours first team used up 150*3 = 450 kg
the second team used up 200 * 3 = 600 kg
however the first team had 1.5 times as much as second team had after three hours.
After three hours;
the amount second team had leftover was y - 600
the amount first team had leftover was x - 450
the amount the second team had ,multiplied by 1.5 is equal to what the first team had
we can build the 2nd equation using this information
1.5 * (y-600) = x-450
1.5y - 900 = x - 450
rearrange the equation,
1.5y - x = -450 +900
2) 1.5y - x = 450
add 1st and 2nd equations to eliminate x
1) + 2) (x - y = -50) + (1.5y - x = 450)
1.5y - y = 450 -50
0.5y = 400
y = 400/ 0.5
y = 800 kg
substitute y = 800 in x = y - 50
x = 800 - 50
x = 750 kg
first team received 750 kg and second team received 800 kg
If you know the radius of the circle do radius times 2.
1,292.50
add 72.15 to the initial balance, then subtract 5.79
