The average fun size Snickers bar has the mass of 20.1 grams with a standard deviation of 0.7 grams What percent of Snickers bars have a mass more than 21.5 grams?

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

Expert Answer

50

step-by-step explanation:

a 4/6 = 9/12   not proportional

step-by-step explanation:

to find which are not proportional, we can use cross products

if it is true, they are proportional.   if it is not true, they are not proportional.

a 4/6 = 9/12

4* 12 = 6*9

48 = 54

not this is not proportional  

b 2/3 = 12/18  

2* 18 = 3 * 12

36 = 36

this is proportional

c 5/4 = 10/8  

5*8 = 4*10

40 = 40

this is proportional

d 7/5 = 35/25

7*25 = 5 * 35

175 = 175

is proportional