Answer: Space was alloted for each subject is 8 dm, 8 dm, 12 dm.
Explanation:
Since we have given the length of bulletin board =28 dm
Let the share of three subject areas be 2x,2x,3x
According to question,
so x=4 dm
Now,
Space was alloted for each subject is given as below:
First subject =
Second subject =
Third subject =
Given:
n = 20, sample size
xbar = 17.5, sample mean
s = 3.8, sample standard deiation
99% confidence interval
The degrees of freedom is
df = n-1 = 19
We do not know the population standard deviation, so we should determine t* that corresponds to df = 19.
From a one-tailed distribution, 99% CI means using a p-value of 0.005.
Obtain
t* = 2.8609.
The 99% confidence interval is
xbar +/- t*(s/√n)
t*(s/√n) = 2.8609*(3.8/√20) = 2.4309
The 99% confidence interval is
(17.5 - 2.4309, 17.5 + 2.4309) = (15.069, 19.931)
Answer: The 99% confidence interval is (15.07, 19.93)
There ya go, the graphing
