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.
The third one tells us the price is $12 per liter, that is to say, the top number is twelve times the bottom number.
.25 × 12 = $3
.7 × 12 = $8.40
2.5 × 12 = $30
3.52 × 12 = $42.24
$57.60 / 12 = 4.80 liters
Answer: x= -63/4, 15 3/4 or 15.75 in decimal form
Step-by-step explanation: Symbolab is a good calculator
Answer:
a) At $3,300 for 600 seats, the average price per seat is 3300/600 = $5.50. The mix of tickets that results in that average can be found using an X diagram as shown below. The numbers on the right are the differences along the diagonals. When they are multiplied by 2, they add to 600. This shows that the required sales for revenue of $3,300 are
200 adult tickets
400 student tickets
b) When 3 student tickets are sold for each adult ticket, the average seat price is
(3*$4.50 +7.50)/4 = $5.25
Then the shortfall in revenue is ...
$3,300 -480*$5.25 = $780
