Answer:
-25
Step-by-step explanation:
Answer:
B. Sample mean used to estimate a population mean.
C. Sample variance used to estimate a population variance.
D. Sample proportion used to estimate a population proportion.
Step-by-step explanation:
This is because the mean of the sampling distribution of the mean tends to target the population mean. Also, the mean of the sampling distribution of the variance tends to target the population variance.
This means that the sample mean and variance tend to target the population mean and variance, respectively, instead of systematically tending to underestimate or overestimate that value. This is why sample means and variances are good estimators of population means and variances, respectively. This is also true for proportions but not true for medians, ranges and standard deviations.
Answer:
Option D. 5890.5 feet²
Step-by-step explanation:
An individual head of a sprinkler system covers a circular are of grass with a radius of 25 feet.
Yard has three sprinkler heads that each cover circular area with no overlap.
We have to calculate the approximate area watered by these 3 sprinkler heads.
Area covered by one sprinkler = π×r² = π×(25)² = 625π feet²
Therefore area covered by three sprinkler heads = 3 × 625π = 5892.85 feet²
which matches the approximate value of Option D. 5890.5 feet²
Answer:
C
Step-by-step explanation:
ratio of red : blue = 4 : 6 = 2 : 3 ← in simplest form