The original price is $450.
<u>Step-by-step explanation:</u>
Step 1:
Given details, Discount%, D% = 30 and Selling Price, SP = $315
Step 2:
Write down formula for calculating the Original Price
Selling Price (SP) = Original Price (OP) - Discount (D)
Discount (D) = Original Price (OP) * (D%/100)
Step 3:
Substitute given values in the formula
315 = OP - D
D = 
D = 0.3 OP
Step 4:
Substitute value of D in the first formula
315 = OP - 0.3 OP
315 = OP (1 - 0.3) = 0.7 OP
Original Price, OP = 315/0.7 = $450
Answer:
1024pi cm²
Step-by-step explanation:
4pi(16)²
4pi256
1024pi
Answer:
(53.812 ; 58.188) ; 156
Step-by-step explanation:
Given that :
Sample size (n) = 51
Mean (m) = 56
Standard deviation (σ) = 9.5
α = 90%
Using the relation :
Confidence interval = mean ± Error
Error = Zcritical * (standard deviation / sqrt (n))
Zcritical at 90% = 1.645
Error = 1.645 * (9.5 / sqrt(51))
Error = 1.645 * 1.3302660
Error = 2.1882877
Hence,
Confidence interval :
Lower boundary = 56 - 2.1882877 = 53.8117123
Upper boundary = 56 + 2.1882877 = 58.1882877
Confidence interval = (53.812 ; 58.188)
2.)
Margin of Error (ME) = 1.25
α = 90%
Sample size = ((Zcritical * σ) / ME)^2
Zcritical at 90% = 1.645
Sample size = ((1.645 * 9.5) / 1.25)^2
Sample size = (15.6275 / 1.25)^2
Sample size = 12.502^2 = 156.3000
Sample size = 156
