Answer:
7. 1520.53 cm²
8. 232.35 ft²
9. 706.86 m²
10. 4,156.32 mm²
11. 780.46 m²
12. 1,847.25 mi²
Step-by-step explanation:
Recall:
Surface area of sphere = 4πr²
Surface area of hemisphere = 2πr² + πr²
7. r = 11 cm
Plug in the value into the appropriate formula
Surface area of the sphere = 4*π*11² = 1520.53 cm² (nearest tenth)
8. r = ½(8.6) = 4.3 ft
Plug in the value into the appropriate formula
Surface area of the sphere = 4*π*4.3² = 232.35 ft² (nearest tenth)
9. r = ½(15) = 7.5 m
Surface area of the sphere = 4*π*7.5² = 706.86 m² (nearest tenth)
10. r = ½(42) = 21 mm
Plug in the value into the formula
Surface area of hemisphere = 2*π*21² + π*21² = 2,770.88 + 1,385.44
= 4,156.32 mm²
11. r = 9.1 m
Plug in the value into the formula
Surface area of hemisphere = 2*π*9.1² + π*9.1² = 520.31 + 260.15
= 780.46 m²
12. r = 14 mi
Plug in the value into the formula
Surface area of hemisphere = 2*π*14² + π*14² = 1,231.50 + 615.75
= 1,847.25 mi²
Answer:
x = -5 ±4sqrt(3)
Step-by-step explanation:
(x + 5)^2 = 48
Take the square root of each side
sqrt((x + 5)^2) = ±sqrt(48)
x+5 = ±sqrt(16*3)
x+5 = ±4sqrt(3)
Subtract 5 from each side
x = -5 ±4sqrt(3)
Answer:
coefficient of the term of degree 4 in this polynomial is 3
Step-by-step explanation:
Y = 2/3x - 6
-2/3x + y = -6...multiply everything by -3
2x - 3y = 18 <== standard form
Answer:
Confidence Interval for the mean
Step-by-step explanation:
Confidence interval is made using the observations of a <em>sample</em> of data obtained from a population, so it is constructed in such a way, that, with a certain <em>level of confidence </em>(this is the statement mentioned in the question), that is, one could have a percentage of probability that the interval, or range around the value obtained, frequently 95%, contains the true value of a population parameter (in this case, the population mean).
It is one way to extract information from a population using a sample of it. This kind of information is what inference statistic is always looking for.
An <u>approximation</u> about how to construct this interval or range:
- Select a random sample.
- For the specific case of a <em>mean</em>, you need to calculate the mean of the <em>sample </em>(sample mean), and, if standard deviation is unknown or not mentioned, also calculate the sample standard deviation.
- With this information, and acknowledged that these values follows a standard normal distribution (a normal distribution with mean 0 and a standard deviation of 1), represented by random variable Z, one can use all this information to calculate a <em>confidence interval for the mean</em>, with a certain confidence previously choosen (for example, 95%), that the population mean must be in this interval or <em>range around this sample mean.</em>
