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This is a general question about sample variance. What is a degree of freedom? The reference page given in my Stat textbook doesn't mention it by name, and could not find it here. Thanks so much!

For 14.4, problem 2: I think you got the wrong answer... p= .05 in the beginning, and you looked up .5 on the chart. Look out for this!

Chapter 8.2, Problem 7: I noticed for the other problems, we did the opposite or alternative for each value. Ho to Ha. How come we didn't do the alternative one for problem 7?

30. The following Minitab display was created from speed data collected on a strip of I-95 where the
speed limit is posted as 55mph. Use the Minitab display below to identify the point estimate for
the population mean, and interpret the 95% confidence interval provided by Minitab.

I am not sure how this went completely over my head and i know the answer is in my face. can you shed some light on this please professor.

hi professor, im having some trouble with a binomial random variable question and I was hoping that you could clarify. the problem is as follows P(170 less than equal to x less than 180) when n = 600 p = .3 I know that the mean is 180 and the standard dev. is 11.2249
but is it as simple as just finding the area from 170 to the mean or am I over simplifying ?

Professor I section 7.3 question number 3
A child psychologist wants to estimate the time it takes a child to respond to a question
with a lie while playing the video game Tetris. If the researcher wants to estimate the
average time to respond within a margin of error of 0.10 seconds, and he wants to use
98% confidence, how many children does he have to time while they attempt to
respond with a lie? Assume the standard deviation of response times is 0.6 seconds.

i got 196 children
i used 2.33 for Z is that where i got it wrong ?