Since 25% is smack in the middle between 20% and 30%, it will take equal volumes of ech to make a 25% solution.
Since 4 gallons of 30% solution was used, so 4 gallons of 20% solution will be needed.
1. 12 feet = 144 inches
15 feet = 180 inches
144 inches / 8 inches = 18
180 inches / 10 inches = 18
The scale factor was 18.
2. Volume = Length x Width X height:
Volume = 16 x 13 x 11 = 2,288 cubic inches.
The houses can be placed in 362,880 ways.
<u>Step-by-step explanation:</u>
The 9 houses are each in different design.
The each lot can place any of the 9 houses.
- The 1st lot can place anyone house of all the 9 houses.
- The 2nd lot can place one of remaining 8 houses.
- The 3rd lot can place one of remaining 7 houses.
Similarly, the process gets repeated until the last house is placed on a lot.
<u>From the above steps, it can be determined that :</u>
The number of ways to place the 9 houses in 9 lots = 9!
⇒ 9×8×7×6×5×4×3×2×1
⇒ 362880 ways.
Therefore, the houses can be placed in 362880 ways.
Answer:
d. There is a 98% chance that the true proportion of customers who click on ads on their smartphones is between 0.56 and 0.62.
Step-by-step explanation:
Confidence interval:
x% confidence
Of a sample
Between a and b.
Interpretation: We are x% sure(or there is a x% probability/chance) that the population mean is between a and b.
In this question:
I suppose(due to the options) there was a small typing mistake, and we have a 98% confidence interval between 0.56 and 0.62.
Interpreation: We are 98% sure, or there is a 98% chance, that the true population proportion of customers who click on ads on their smartphones is between 0.56 and 0.62. Option d.
This is what I got for the factors: (2x-7) and (3x^3-2x+5).