Answer:36 postcards
Step-by-step explanation:
jenny bought 12 post cards
joe bought half of the postcards jenny bought = 12/2 = 6
ruth bought 3 times the postcards joe bought = 3 x 6 = 18
total postcards bought by all = 12 + 6 + 18 = 36 postcards
Answer:

Step-by-step explanation:
Hint- First we have to calculate the mean and standard deviation of the sample and then applying formula for confidence interval we can get the values.
Mean of the sample is,

Standard deviation of the sample is,

The confidence interval will be,

Here,
Z for 95% confidence interval is 1.96, and n is sample size which is 24.
Putting the values,



Confidence interval is used to express the degree of uncertainty associated with a sample.
95% confidence interval means that if we used the same sampling method to select different samples and calculate an interval, we would expect the true population parameter to fall within the interval for 95% of the time.
Answer:
Multiplying a Monomial by a Monomial. When multiplying a monomial by a monomial, we multiply the coefficients together and tack on the variables at the end (usually in alphabetical order). When multiplying two of the same variables, add the exponents. Remember that the exponent on x is an invisible 1.
Step-by-step explanation:
Hope this helps
I would start by saying how much I enjoyed this lesson and how it has helped me in many ways I would also like to state how it was difficult at first but once I started to understand it, it became really easy and would like to thanks the teacher for teaching it.