Question

In: Statistics and Probability

1-The mean speed of vehicles along a stretch of highway is 75 miles per hour with...

1-The mean speed of vehicles along a stretch of highway is 75 miles per hour with a standard deviation of 3.8 miles per hour. Your current speed along this stretch of highway is 62 miles per hour. What is the z-score for your speed?

z- score =_______ (Round to two decimal places)

2- For a statistics test the mean is 63 and the standard deviation is 7.0, and for a biology test the mean is 23 and the standard deviation is 3.9. A student gets a 60 on the statistics test and a 22 on the biology test, on which of the two tests the student perform better?

Group of answer choices

Biology

Statistics

Both are equal

3- A member is selected at random from the population represented by the graph. Study the picture and use the information gathered to find the probability that the member selected at random is from the shaded region of the graph.

The area of the shaded region is__________ (Round answers to 4 decimal places)

4- A random sample of 50 cars in the drive-thru of a popular fast food restaurant revealed an average bill of $18.21 per car. The population standard deviation is $5.92.

Round your answers to two decimal places.

(a) State the point estimate for the population mean cost of fast food bills at this restaurant $

(b) Calculate the 95% margin of error. $

(c) State the 95% confidence interval for the population mean cost of fast food bills at this restaurant.

$ ≤ µ ≤ $

(d) What sample size is needed if the error must not exceed $1.00?

n =

5- Assume that females have pulse rates that are normally distributed with a mean of 74.0 beats per minute and a standard deviation of 12.5 beats per minute.

(a) If 1 adult female is randomly selected, find the probability that her pulse rate is less than 80 beats per minute. (Round your answer to 4 decimal places)

(b) If 16 adult females are randomly selected, find the probability that they have pulse rates with a mean less than 80 beats per minute. (Round your answer to 4 decimal places)

Expert Solution

orchestra answered 3 years ago

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