A study found that for a sample of cars traveling on Interstate 70, the average speed was 70 mph with a 90% confidence interval for the population mean speed of drivers of (66 mph, 76 mph).  How do you find the margin of error for this confidence interval? Show work please.

A student scored between 81% and 93% on all exams except for one that she failed with a 47% because she studied the wrong chapters. Which value would better represent hertypical performance: mean exam grade or median exam grade? Briefly explain.

A basketball coach kept stats for his team in free throw percentage and steals (among others). At the last game, Erin’s free throw percentage was 79% and she had 4 steals. The team averaged 90% from the free throw line with a standard deviation of 12% and they averaged 5 steals with a standard deviation of 4. In which category did Erin do better compared with her team? Explain using z-score.

Please help me better understand the practice problem from my textbook, how to solve it and interpret the conclusion.

Lucas and Alex began arguing about who did better on their tests, but they couldn't decide who did better given that they took different tests. Lucas took a test in Math and earned a 73.4, and Alex took a test in English and earned a 70.5. Use the fact that all the students' test grades in the Math class had a mean of 74.1 and a standard deviation of 11.3, and all the students' test grades in English had a mean of 60.9 and a standard deviation of 8.1 to answer the following questions.a) Calculate the z-score for Lucas's test grade.z=z=b) Calculate the z-score for Alex's test grade.z=z=

The blue catfish (Ictalurus Furcatus) is the largest species of North Amercian catfish. The current world record stands at 143 pounds, which was caught in the John H. Kerr Reservoir (Bugg's Island Lake) located in Virginia. According to Amercian Expedition, the average weight of a blue catfish is between 20 to 40 pounds. Given that the largest blue catfish ever caught was at the John H. Kerr Reservoir, you believe that the mean weight of the fish in this reservoir is greater than 40 pounds.a) If you going to test this claim at the 0.05 significance level, what would be your null and alternative hypotheses?H0H0:               H1H1:               b) What type of hypothesis test should you conduct (left-, right-, or two-tailed)? left-tailed right-tailed two-tailed

Please see picture. Need this asap please and thank you.

Many students did an exam, the mean was 15 and the standard deviation was 32 The highest mark was X= 103, What is the zscore of the highest mark?

The blue catfish (Ictalurus Furcatus) is the largest species of North Amercian catfish. The current world record stands at 143 pounds, which was caught in the John H. Kerr Reservoir (Bugg's Island Lake) located in Virginia. According to Amercian Expedition, the average weight of a blue catfish is between 20 to 40 pounds. Given that the largest blue catfish ever caught was at the John H. Kerr Reservoir, you believe that the mean weight of the fish in this reservoir is greater than 40 pounds. Use the data below, which represents the summary statistics for 50 blue catfish caught at this reservoir, and a 0.05 significance level to test the claim that the mean weight of the fish in the John H. Kerr Reservoir is greater than 40 pounds. n=50;  ¯x=40.72 pounds;  s=5.03pounds Calculate your test statistic. Write the result below, and be sure to round your final answer to two decimal places.e) Calculate your p-value. Write the result below, and be sure to round your final answer to four decimal…

On a verbal skill test, the mean was 72 and the standard deviation was 7. If John scored 75, what was his z-score?