Answer:
Step-by-step explanation:
We want to determine a 90% confidence interval for the true population mean textbook weight.
Number of sample, n = 22
Mean, u = 64 ounces
Standard deviation, s = 5.1 ounces
For a confidence level of 90%, the corresponding z value is 1.645. This is determined from the normal distribution table.
We will apply the formula
Confidence interval
= mean ± z ×standard deviation/√n
It becomes
64 ± 1.645 × 5.1/√22
= 64 ± 1.645 × 1.087
= 64 ± 1.788
The lower end of the confidence interval is 64 - 1.788 = 62.21 ounces
The upper end of the confidence interval is 64 + 1.788 = 65.79 ounces
Therefore, with 90% confidence interval, the true population mean textbook weight is between 62.21 ounces and 65.79 ounces
Answer:
D
Step-by-step explanation:
it is a quadratic trinomial
Answer:
x = 36
Step-by-step explanation:
Cross multiplication yields:
20x = 24(30), or
x = 24(30)/20 = 36
Answer:
start on point (0,2) and go up 3 over 1 and mark that point...continue with the pattern and draw the line connecting all the points
Step-by-step explanation:
when youre done it should look like this
2cos²x+cos x-1=0
cos x=t
2t²+t-1=0
t=[-1⁺₋√(-1+8)]/2=(-1⁺₋3)/4
We have two possible set solutions:
First set solutions.
t₁=(-1-3)/2=-4/4=-1
cos x=-1 ⇒x=cos⁻¹ (-1)=π +2kπ or 180º+360ºk (k=(...-2,-1,0,1,2...)
Second set solutions:
t₂=(-1+3)/4=2/4=1/2
cos x=1/2 ⇒ x=cos⁻¹ 1/2=π/3+2kπ U 5π/3+ 2kπ or
60º+360ºK U 300º+360ºK (k=...-2,-1,0,1,2,...)
solutions: first set solutions U second set solutions:
Answer in radians : π +2kπ U π/3+2kπ U 5π/3+ 2kπ (k=...-1,0,1,...)
Answer is degrees: 180º+360ºk U 60º+360ºK U 300º+360ºK (k=...-2,-1,0,1,2,...)
