Answer:
to get x by itself so divide 5 by 2 and then add 7 to the other side
Step-by-step explanation:
2x-7=5
x-7=2.5
x=2.5+7
x=9.5
Answer:
102471 sq .in the land answer Teri ma ki bosra
Answer:
28.27 in²
Step-by-step explanation:
The area of a circle is dependent on only one variable: the radius:
A = πr²
If the radius is 3 inches, as you seem to indicate, then:
A = π(3 in)² = 9π in² = 28.27 in²
Answer:
Step-by-step explanation:
We want to determine a 90% confidence interval for the mean amount of time that teens spend online each week.
Number of sample, n = 41
Mean, u = 43.1 hours
Standard deviation, s = 5.91 hours
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
43.1 ± 1.645 × 5.91/√41
= 43.1 ± 1.645 × 0.923
= 43.1 ± 1.52
The lower end of the confidence interval is 43.1 - 1.52 =41.58
The upper end of the confidence interval is 43.1 + 1.52 =44.62
Therefore, with 90% confidence interval, the mean amount of time that teens spend online each week is between 41.58 and 44.62
The associative property states that we can add numbers in any way we want to still get the same sum, so the parenthesis here can essentially be tossed out to get 3x+2-5=3x-3. However, make sure, for example, that you don't add x and 1 together in 3(x)+1 as you still have to multiply the x with 3 before adding the 1 according to PEMDAS
