<span>4x^2 - 36 = 0 ( Original equation )
4x^2 = 36 ( Add 36 to both sides )
x^2 = 9 ( Divide by 4 on both sides )
x = 3 , -3 ( Take the square root of 9 )
Solution set: { +3 , -3 } answer is x = +3 , x = -3</span>
Answer:
90% confidence interval for the population mean is between a lower limit of $92.18 and an upper limit of $107.82.
Step-by-step explanation:
Confidence interval for a population mean is given as mean +/- margin of error (E)
mean = $100
sd = $25.20
n = 30
degree of freedom = n-1 = 30-1 = 29
confidence level (C) = 90% = 0.9
significance level = 1 - C = 1 - 0.9 = 0.1 = 10%
critical value (t) corresponding to 29 degrees of freedom and 10% significance level is 1.699
E = t×sd/√n = 1.699×25.20/√30 = $7.82
Lower limit of population mean = mean - E = 100 - 7.82 = $92.18
Upper limit of population mean = mean + E = 100 + 7.82 = $107.82
90% confidence interval is ($92.18, $107.82)
Answer: Each dozen of chocolate chip cookies costs $1.50/dozen. So if you sell C dozens of them, you win C*$1.50 dollars, where C is a positive integer number. Similar case for the lemon ones, the baker will win L*$1.00 dollars if he sells L dozens of them ( where L is a positive integer), the total charge is the sum of both parts; T = L*$1.00 + C*$1.50.
From the law of sines, we have:

,
where x and y are the sides opposite to angles X and Y, respectively.
Substituting the known values, we have:

, thus

.
Using a calculator, we can find that arcsin(0.31)=18 degrees, approximately.
We know that sine of (180-18)=162 degrees is also 0.31. But 162 and 51 degrees add up to more than 180 degrees.
Thus, there is only one triangle that can be formed under these conditions.