Answer:
mean=4.44
standard deviation=1.67
Step-by-step explanation:
The mean and standard deviation for the number of erroneous returns per batch can be calculated using binomial distribution. The binomial distribution is used because
i) There are one of two possible outcomes( error or no error) that can be categorized into success and failure.
ii) The experiment is repeated fix number of times 12.
iii) The probability of success remains constant at each trial i.e. 37%
iv) The trails are independent.The mean and standard deviation of binomial distribution are np and √npq
Here, n=12, p=0.37 and q=1-0.37=0.63
mean=12*0.37=4.44
standard deviation=√12*0.37*0.63=√2.8=1.67
B.addition property of multiplication
D.inverse property of multiplication
E.commutative property of addition
Answer:
a)
So then we can conclude that the true proportion of women with cosmetic dermatitis from using eye shadow at 95% of confidence is between (0.0422 and 0.1410)
b) 
So then we can conclude that the true proportion of women with cosmetic dermatitis from using mascara at 95% of confidence is between (0.0628 and 0.1372)
c) For this case we see that both confidence intervals contains the value of 0.12 so then we can't conclude that only one group is referenced at the significance level of 0.05 used.
Step-by-step explanation:
Part a
The estimated proportion of women with cosmetic dermatitis from using eye shadow is given by:

The confidence interval is at 95% of confidence, our significance level would be given by
and
. And the critical value would be given by:
The confidence interval for the proportion is given by the following formula:
Replacing we got:
So then we can conclude that the true proportion of women with cosmetic dermatitis from using eye shadow at 95% of confidence is between (0.0422 and 0.1410)
Part b: A 95% confidence interval for the women with cosmetic dermatitis from using mascara

So then we can conclude that the true proportion of women with cosmetic dermatitis from using mascara at 95% of confidence is between (0.0628 and 0.1372)
Part c: Suppose you are informed that the true proportion with a nickel allergy for one of the two groups (eye shadow or mascara) is .12. Can you determine which group is referenced? Explain.
For this case we see that both confidence intervals contains the value of 0.12 so then we can't conclude that only one group is referenced at the significance level of 0.05 used.
Complete Question:
The weather forecast for next season calls for a 10% chance of wind, a 20% chance of rain, a 30% chance of clouds, and a 40% chance of sunshine. If there are 90 days in the season,spin the spinner 90 times to simulate the 90-day weather forecast. Which type of weather has the lowest observed frequency?
Answer:
Wind Weather
Step-by-step explanation
From the question above
The sample space(which means the total number of events that we are considering ) = 90 times of spinning which represents the 90 days weather forecast
The chance of wind weather occurring is 10% and its observed frequency of occurrence within the 90 days is =
= 9 days
The chance of rain weather occurring is 20% and its observed frequency of occurrence within the 90 days is =
= 18 days
The chance of cloud weather occurring is 30% and its observed frequency of occurrence within the 90 days is =
= 27 days
The chance of sunshine weather occurring is 40% and its observed frequency of occurrence within the 90 days is =
= 36 days
We see from the above calculation that the weather with the lowest observed frequency is Wind weather
Answer:
The correct answers are 40, 120, 240, and 320
Step-by-step explanation:
.