1256.64 is the area, because you use this equation- A=πr^2
Answer:
12
Step-by-step explanation:
- 4x - y + 4
If x = - 14 and y = 3, we just plug in and solve
- 4(14) - (3) + 4
- 56 - 3 + 4
- 56 + 1
- 55
Answer:
1,539
Step-by-step explanation:
Using Simple Random Sampling in an infinite population (this is such a large population that we do not know the exact number) we have that the sample size should be the nearest integer to
where
<em>Z= the z-score corresponding to the confidence level, in this case 90%, so Z=1.645 (this means that the area under the Normal N(0,1) between [-1.645,1.645] is 90%=0.9)
</em>
<em>p= the proportion of young urban people (ages 21 to 35 years) who go to at least 3 concerts a year= 35% = 0.35
</em>
<em>q = 1-p = 0.65
</em>
<em>e = the error proportion = 2% = 0.02
</em>
Making the calculations
So, the sample size should be 1,539 young urban people (ages 21 to 35 years)
Step-by-step explanation:
The “fun size” of a Snickers bar is supposed to weigh 20 grams. Because the penalty for selling Snickers candy bars that weigh less than 20 grams is so severe, the manufacturer calibrates the machine so that the mean weight is 20.2 grams. The quality control manager at the candy company is concerned that the candy produced does not weigh 20.2 grams. She obtains a random sample of 64 candy bars and weighs them. She finds that the mean weight of this sample is 20.05 grams with standard deviation 0.72. By answering the following questions, test the claim that the Snickers bars have a mean weight less than 20.2 grams at the level of α = 0.01.
1. Select from the following list all the requirements that are met in this problem scenario for this test: (circle your choice(s))
a. The population is approximately normal.
b. The population standard deviation is known.
c. The sample taken is a random sample.
d. The population standard deviation is unknown. e
. The degrees of freedom is 0.01.
f. The sample size is greater than 30.
2. Which of the following statements is correct?
a) Parameters describe sample characteristics.
b) Statistics describe population characteristics.
c) We use statistics to estimate the value of parameters.
d) We use parameters to estimate the value of statistics
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