The given problem describes a binomial distribution with p = 60% = 0.6. Given that there are 400 trials, i.e. n = 400.
a.) The mean is given by:

The standard deviation is given by:

b.) The mean means that in an experiment of 400 adult smokers, we expect on the average to get about 240 smokers who started smoking before turning 18 years.
c.) It would be unusual to observe <span>340 smokers who started smoking before turning 18 years old in a random sample of 400 adult smokers because 340 is far greater than the mean of the distribution.
340 is greater than 3 standard deviations from the mean of the distribution.</span>
Answer:
Point Estimate for different between population means = - 0.99
Step-by-step explanation:
We are given data of two samples and we have to find the best point estimate of the true difference between two population means. Remember that in absence of data about population the best estimator is the sample data. So, we will find the means of both sample data and find the difference of that means. This difference between the means of sample data will be the best point estimate for the true difference between the population means.
Formula to calculate the mean is:

Mean of Sample 1:

Mean of Sample 2:

Therefore the best point estimate for difference between two population means would be = Mean of Sample 1 - Mean of Sample 2
= 128.55 - 129.54
= - 0.99
Simple actually. The 1000 is the starting price the -20 is the losing of value per week and the w stands for the number of weeks.
(See the imagine for reference)
Let’s solve where they have a triangle, so the height is 9 cm, the base is 3 cm:
1/2 • 9 • 3 = 13.5
Since there’s 2 triangles we do:
13.5(2) = 27
Now the rectangle in the middle, where the height is 9cm and the base is 12cm:
12 • 9 = 108
Add up the areas:
108 + 27 = 135