Answers:
Mean - 85.2
Median - 85
Mode - 85
Explanation:
Mean - 77+85+85+86+93=426/5 (the amount of data points given) = 85.2
Median - Organize the data points from least to greatest and eliminate the outermost numbers two at a time (one from both side) until you’re left with one.
Mode - The number that appears the most often in a given data set
Answer:
Yes there is sufficient evidence to reject the company's evidence
Step-by-step explanation:
From the question we are told that
The sample size is n = 25
The mean is
The standard deviation is 
The z-score is z = -1.94
The null hypothesis is 
The alternative hypothesis is 
Generally the p-value is mathematically evaluated as

From the z table the area under the normal curve to the left corresponding to -1.94 is

=> 
=> 
Let assume the level of significance is 
Hence the
this mean that
The decision rule is
Fail to reject the null hypothesis
The conclusion is
There is sufficient evidence to reject the company's evidence
13: multiply the amount by the tax rate (to make a percent a decimal move the decimal point 2 places to the left) and add the original amount and the taxed amount together. For 12 do above but then multiply the total by the tip rate and add together (basically the same as the tax again) :) I hope this helps