Answer:
see below
Step-by-step explanation:
The equation to determine the work time is
1/a+1/b = 1/c where a and b are the times alone and c is the time together
1/80 + 1/30 = 1/c
Multiply by the least common denominator to clear the fractions, which is 240c
240c(1/80 + 1/30 = 1/c)
3c+8c = 240
11c = 240
Divide by 11
11c/11 =240/11
c = 240/11 minutes
c=21.81818
Approximately 22 minutes
Answer:
5789 digits
Step-by-step explanation:
Given that the number of pages ares: 1,724
As we know that:
- (from 1 - 9) there are 9 one-digit numbers
- (from 10- 99) there are 90 two-digit numbers
- (from 100 - 999) there are 900 three-digit numbers
- (from 1,000 - 1,724) there are 725 four-digit numbers
So the total are:
![= 9(1)+90(2)+900(3)+725(4)\\\\= 9+180+2,700+2,900\\\\= 5,789\ digits](https://tex.z-dn.net/?f=%3D%209%281%29%2B90%282%29%2B900%283%29%2B725%284%29%5C%5C%5C%5C%3D%209%2B180%2B2%2C700%2B2%2C900%5C%5C%5C%5C%3D%205%2C789%5C%20digits)
Answer:
Option 2 is true.
Step-by-step explanation:
Th sum of probabilities of two complementary events is one, which implies
P(A) + P(B) = 1
So,
P(B) = 1 - P(A)
Answer:
H0 : μ = 2
H1 : μ > 2
We fail to reject the null and conclude that no significant evidence exists to support that mean tree-planting time differs from two hours.
Step-by-step explanation:
Given :
X = 23.71,17.79,29.87,18.78,28.76
Sample mean, xbar = Σx / n = 22/10 = 2.2
Standard deviation, s = 0.516 (calculator)
H0 : μ = 2
H1 : μ > 2
Test statistic :
(xbar - μ) ÷ (s/sqrt(n))
n = 10
Test statistic :
(2.2 - 2) ÷ (0.516/sqrt(10))
0.2 / 0.1631735
Test statistic = 1.23
Using the Pvalue from Tscore calculator, df = n - 1 = 10 - 1 = 9
Pvalue(1.23, 9) = 0.1249
Since, Pvalue > α ; We fail to reject the null and conclude that no significant evidence exists to support that mean tree-planting time differs from two hours.