Answer:
a) The formula is given by mean 
the margin of error. Where the margin of error is the product between the critical value from the normal standard distribution at the confidence level selected and the standard deviation for the sample mean.
b) 
Step-by-step explanation:
Previous concepts
A confidence interval is "a range of values that’s likely to include a population value with a certain degree of confidence. It is often expressed a % whereby a population means lies between an upper and lower interval".
The margin of error is the range of values below and above the sample statistic in a confidence interval.
Normal distribution, is a "probability distribution that is symmetric about the mean, showing that data near the mean are more frequent in occurrence than data far from the mean".
If the distribution for X is normal or if the sample size is large enough we know that the distribution for the sample mean 
is given by:
Part a
The formula is given by mean the margin of error. Where the margin of error is the product between the critical value from the normal standard distribution at the confidence level selected and the standard deviation for the sample mean.
Part b
The confidence interval for the mean is given by the following formula:
Answer:
3/4
Step-by-step explanation:
Use the rise over run equation
Whats the question? I dont understand whats happenign here.
Answer:
26 and 32. The product (multiplied together) is 832.
Answer:
77.5%
Step-by-step explanation:
The question gives the first laptop price, the first discount and the subsequent discount. This is therefore how we will go about obtaining the total percentage discount;
Price of New Laptop = $1500
New Price after first discount = $1500 - (10% of $1500) = $1500 - $150 = $1350
Then an additional 75% discount gives: $1350 - (75% of $1350) = $1350 - $1012.50 = $337.50
Now, the total discount is the difference in the first laptop price ($1500) and this current price: $1500 - $337.50 = $1162.50
The total percentage discount = 
× 100% = 
× 100% = 77.5%
