Answer:
1) The correct z* to to construct a 92% confidence interval is 1.75
2) these results are not good evidence that the new curriculum has improved Math SAT scores.
3) the results are not statistically significant at level α = 0.05, but they are practically significant.
Step-by-step explanation:
1) z-score for 92% confidence level is ≈ 1.75
2) P-value for testing whether the mean score in senator's state is more than the national average of 480 is less than 0.0001 means that
the probability that the sample is drawn from the population where senator's state is more than the national average of 480 is <0.0001.
Thus we have to reject this hypothesis since the probability is too small.
3) if we calculate the statistic of the sample we get (560-480)/100=0.8 where
- 560 is the mean score of trained 4 students
- 480 is the mean math sat score of this year
- 100 is the standard deviation of the test.
Since t-critical at 0.05 significance for 3 degrees of freedom ≈ 2.35 is bigger than 0.8, the result is not significant statistically.
But 80 points higher than the national average is a practically significant result since its <em>effect size</em> is large.
Answer: 
Step-by-step explanation:
We are given the following formula, used to calculate the value of an used car according to the years after the car was originally bought:
Where 
is the price of the car when it was bought new, and 
is the number of years the car was used.
Solving the formula with the given data:
This is the value of the car according to the formula.
However, this value can be approximated to:
2.95 =
(simplifying)
(times by the bottom and add the top)
Answer: 78 rupees
Explanation: since 10 pens cost 60 rupees you can divide 60 by 10 to get the cost of a single pen. The cost of a single pen is 6 rupees so you can multiply that by 13 to find the cost of the 13 pens.
10p=60
60/10=6
p=6
so
13x6=78
Hope this helped! :)
