I will send you a hopefully helpful link. https://www.ncdc.noaa.gov/sotc/national/201403
Answer:
Proportion states that the two fractions or ratios are equal
Given the equation: 
By cross multiply we get;

Using distributive property; 

Subtract 0.4 from both sides we get;

Subtract 1.5x from both sides we get;

Divide both sides by 0.1 we get;

Simplify:
x = 56
Therefore, the value of x that satisfy the equation
is, 56
Answer:
Step-by-step explanation:
In each option you need to find the number of outcomes of a single event and then multiply that by the number of times that event takes place.
1. 2 outcomes (heads and tails)
2. 6 outcomes (2 outcomes * 3 tosses)
3. 60 outcomes (6 outcomes per die * 10 rolls)
4. 12 outcomes (6 outcomes per die * 2 rolls)
5. 10 outcomes (10 numbers on the pad)
6. 52 outcomes (52 cards in a regular deck)
7. 32 outcomes (32 letters in the alphabet)
8. 7 outcomes (7 letters to choose from)
9. 10 outcomes (10 letters to choose from)
10. 36 outcomes (36 crayons to choose from)
Answer:
95% confidence interval for the proportion of students supporting the fee increase is [0.767, 0.815]. Option C
Step-by-step explanation:
The confidence interval for a proportion is given as [p +/- margin of error (E)]
p is sample proportion = 870/1,100 = 0.791
n is sample size = 1,100
confidence level (C) = 95% = 0.95
significance level = 1 - C = 1 - 0.95 = 0.05 = 5%
critical value (z) at 5% significance level is 1.96.
E = z × sqrt[p(1-p) ÷ n] = 1.96 × sqrt[0.791(1-0.791) ÷ 1,100] = 1.96 × 0.0123 = 0.024
Lower limit of proportion = p - E = 0.791 - 0.024 = 0.767
Upper limit of proportion = p + E = 0.791 + 0.024 = 0.815
95% confidence interval for the proportion of students supporting the fee increase is between a lower limit of 0.767 and an upper limit of 0.815.