It would be 63, because 33 1/3% is the equivalent of 1/3,
21x3 = 63
Answer:
7.5 cups of powder
Step-by-step explanation:
4 cups to 2 cups of water = 1.5 cup of powder
8 cups of water = 6 cups of powder
plus 2 cups of water equals 7.5 cups of powder
3/5 - 1/7
Find the LCM of 5 and 7 to find equivalent fractions for both fractions
LCM = 35
3/5 = 21/35
1/7 = 5/35
So 21/35 - 5/35 = 16/35
I'm pretty sure that's the simplest form because I can't think of a common factor of 16 and 35 by which to reduce it further.
Answer: (14.4, 17.2)
Step-by-step explanation: We are to construct a 98% confidence interval for mean household usage of electricity.
We have been given that
Sample size (n) = 872
Sample mean (x) = 15.8
Population standard deviation (σ) = 1.8
The formulae that defines the 98% confidence interval for mean is given below as
u = x + Zα/2 × σ/√n...... For the upper limit
u = x - Zα/2 × σ/√n...... For the lower limit
Zα/2 = critical value for a 2% level of significance in a two tailed test = 2.33
By substituting the parameters we have that
For upper tailed
u = 15.8 + 2.33 × (1.8/√872)
u = 15.8 + 2.33 (0.6096)
u = 15.8 + 1.4203
u = 17.2
For lower tailed
u = 15.8 - 2.33 × (1.8/√872)
u = 15.8 - 2.33 (0.6096)
u = 15.8 - 1.4203
u = 14.4
Hence the 98% confidence interval for population mean usage of electricity is (14.4kwh, 17.2kwh)
