Let get all the information.
Mean:394
Deviation:35
Looking for At Least 380 feet
To find the z score you take the wanted probality subtract the mean and divide by the deviation.
z=(380-394)/35.
z=-0.4
So far so good.
But when he looked at the table he looked at probability that the home runs are less then 380 feet.
From this table
http://www.stat.ufl.edu/~athienit/Tables/Ztable.pdf
To find the answer you have to take 1-(the probability that the home runs are less than 380 feet)or 1-0.3446=0.6554
He made an error in his calculation.
Answer:
95%
Step-by-step explanation:
In this case we can apply a formula that tells us that:
# (AUB) = #A + #B - #AnB
Where A would be the ones who enjoy swimming and B would be the ones who enjoy running. AnB is the intersection of both sets, that is, those who enjoy doing both things, these values we have, if we replace them we have left:
#(AUB) = 80% + 70% - 55%
#(AUB) = 95%
Which means that 95% of people enjoy either swimming or running
Answer:
1) Fail to reject the Null hypothesis
2) We do not have sufficient evidence to support the claim that the mean distance students traveled to school from their current residence was different for males and females.
Step-by-step explanation:
A university administrator wants to test if there is a difference between the distance men and women travel to class from their current residence. So, the hypothesis would be:

The results of his tests are:
t-value = -1.05
p-value = 0.305
Degrees of freedom = df = 21
Based on this data we need to draw a conclusion about test. The significance level is not given, but the normally used levels of significance are 0.001, 0.005, 0.01 and 0.05
The rule of the thumb is:
- If p-value is equal to or less than the significance level, then we reject the null hypothesis
- If p-value is greater than the significance level, we fail to reject the null hypothesis.
No matter which significance level is used from the above mentioned significance levels, p-value will always be larger than it. Therefore, we fail to reject the null hypothesis.
Conclusion:
We do not have sufficient evidence to support the claim that the mean distance students traveled to school from their current residence was different for males and females.
Bar GraphA graph that uses bars to show dataHorizontal Bar Grapha bar graph in which the bars are read from left to rightKeyThe part of a map or graph that explains the symbols.Line PlotA graph that uses marks to record each piece of data above a number line.Vertical Bar GraphA bar graph in which the bars are read from the bottom to the top.DataInformation gathered and used to make sense.Line Graphused to show how two continuous variables are related; may be used to show how one variable changes over time.circle graphused to display data showing the relationship of parts to a whole<span>Mean</span>
Answer: 
Step-by-step explanation:
For this exercise you need to remember:
1) The mulitplication of signs:

2) By definition, like terms contain the same variables with the same exponent.
Then knowing this, and given the equations:
and 
You must subtract the like terms, which means that you must subtract the numerical coefficients of each term.
Then, you get the result is:
