Solve the system of equations. Use the space provided to show your work. Make sure you assign your variables to the problems given. Obtain the solution by any
method you choose. You must show the check.
A used book store also started selling used CDs and videos. In the first week, the store sold a
combination of 40 CDs and videos. They charged $4 per CD and $6 per video and the total
sales were $180. Determine the total number of CDs and videos sold.

d. 24+-0.114

step-by-step explanation:

the question requires us to calculate the approximate 95% confidence interval for the mean number of ounces of ketchup per bottle in the sample given the following statistics;

sample mean = 24

standard deviation, σ = 0.4

sample size , n = 49

the confidence interval for a population mean is calculated using the formula;

sample mean ± z-score*(σ/sqrt(n))

the z-score associated with a 95% confidence interval, from the standard normal tables, is;

1.96

substituting these values into the formula;

24 ± 1.96*(0.4/7)

= 24 ± 0.112

from the alternatives given, choice d is closest to the above expression;