Monday

March 30, 2015

March 30, 2015

Posted by **jabrony** on Monday, November 28, 2011 at 1:31pm.

33

33

38

33

35

35

40

40

40

31

After

34

28

25

28

35

33

31

28

35

33

Ten different families are tested for the number of gallons of water per day they use before and after viewing a conservation video. Construct a 90% confidence interval for the mean of the differences.

- statistics -
**PsyDAG**, Tuesday, November 29, 2011 at 11:57amSubtract before values from after values.

Find the mean = sum of scores/number of scores

Subtract each of the scores from the mean and square each difference. Find the sum of these squares. Divide that by the number of scores to get variance.

Standard deviation = square root of variance

90% = mean ± 1.645 SD

I'll let you do the calculations.

**Answer this Question**

**Related Questions**

algebra - a barrel contains 163 gallons of water and is being drained at a ...

statistics - the average number of gallons of lemonade consumed by the football ...

algebra - You pull out the plug from the bathtub. After 40 seconds, there are 13...

math - Water is Pumped into an underground tank at a constant rate of 8 gallons ...

probability - PROBLEM 7: SAMPLING FAMILIES (3 points possible) We are given the ...

maths - 1)a linear function is represented by f(x)=2x+7 which of the following ...

Statistics - The daily water consumption for an Ohio community is normally ...

Statistics - A local grocery store wants to estimate the mean daily number of ...

Probability - We are given the following statistics about the number of ...

Algebra - A barrel contains 181 gallons of paint and is being drained at a ...