Using diaries for many weeks, a study on the lifestyles of visually impaired students was conducted. The students kept track of many lifestyle variables including how many hours of sleep obtained on a typical day. Researchers found that visually impaired students averaged 9.83 hours of sleep, with a standard deviation of 2.38 hours. Assume that the number of hours of sleep for these visually impaired students is normally distributed. Give your answers to 4 decimal places. Use at least 3 decimal places for your z-scores. (a) What is the probability that a visually impaired student gets less than 6 hours of sleep? answer. (b) What is the probability that a visually impaired student gets between 6.2 and 8.25 hours of sleep? answer. (C) Thirty percent of students get less than how many hours of sleep on a typical day? hours answer.

in a test of a lifelong brand of tires , a survey revealed that the mean life was 35,000 mikes and the standard deviation was 7083 mikes.  if the shape of the population distribution is known to be normal, approximately what percentage of the tires lasts less than 20834 miles ?

A particular fruit's weights are normally distributed, with a mean of 342 grams and a standard deviation of 14 grams.The heaviest 2% of fruits weigh more than how many grams?Give your answer to the nearest gram.

Pyramid Lake is on the Paiute Indian Reservation in Nevada. The lake is famous for cutthroat trout. Suppose a friend tells you that the average length of trout caught in Pyramid Lake is ? = 19 inches. However, a survey reported that of a random sample of 46 fish caught, the mean length was x = 18.4 inches, with estimated standard deviation s = 2.7 inches. Do these data indicate that the average length of a trout caught in Pyramid Lake is less than ? = 19 inches? Use ? = 0.05. Solve the problem using the critical region method of testing (i.e., traditional method). (Round the your answers to three decimal places.)   test statistic =   critical value =   State your conclusion in the context of the application. Reject the null hypothesis, there is sufficient evidence that the average fish length is less than 19 inches.Reject the null hypothesis, there is insufficient evidence that the average fish length is less than 19 inches.    Fail to reject the null hypothesis, there is…

A particular fruit's weights are normally distributed, with a mean of 609 grams and a standard deviation of 40 grams.The heaviest 20% of fruits weigh more than how many grams?Give your answer to the nearest gram.

Pyramid Lake is on the Paiute Indian Reservation in Nevada. The lake is famous for cutthroat trout. Suppose a friend tells you that the average length of trout caught in Pyramid Lake is ? = 19 inches. However, a survey reported that of a random sample of 51 fish caught, the mean length was x = 18.6 inches, with estimated standard deviation s = 3.1 inches. Do these data indicate that the average length of a trout caught in Pyramid Lake is less than ? = 19 inches? Use ? = 0.05.   a) Estimate the P-value. select one:P-value > 0.0100.0010 < P-value < 0.010 0.250 < P-value < 0.00100.125 < P-value < 0.250P-value < 0.125 b) Sketch the sampling distribution and show the area corresponding to the P-value. c) will you reject or fail to reject the null hypothesis? Are the data statistically significant at level ??At the ? = 0.05 level, we reject the null hypothesis and conclude the data are statistically significant.At the ? = 0.05 level, we reject the null hypothesis and…

Suppose that the distance of fly balls hit to the outfield (in baseball) is normally distributed with a mean of 250 feet and a standard deviation of 44 feet. Let X = distance in feet for a fly ball. Find the 80th percentile of the distribution of fly balls. (Round your answer to one decimal place.)

A successful basketball player has a height of 6 feet 11 ​inches, or 211 cm. Based on statistics from a data​ set, his height converts to the z score of 5.17. How many standard deviations is his height above the​ mean?

Pyramid Lake is on the Paiute Indian Reservation in Nevada. The lake is famous for cutthroat trout. Suppose a friend tells you that the average length of trout caught in Pyramid Lake is ? = 19 inches. However, a survey reported that of a random sample of 51 fish caught, the mean length was x = 18.6 inches, with estimated standard deviation s = 3.5 inches. Do these data indicate that the average length of a trout caught in Pyramid Lake is less than ? = 19 inches? Use ? = 0.05. (a)What is the level of significance? =__   State the null and alternate hypotheses. A-H0: ? = 19 in; H1: ? ≠ 19 in B-H0: ? < 19 in; H1: ? = 19 in  C-H0: ? = 19 in; H1: ? < 19 in D-H0: ? = 19 in; H1: ? > 19 in E-H0: ? > 19 in; H1: ? = 19 in (b)What sampling distribution will you use? Explain the rationale for your choice of sampling distribution. A-The Student's t, since the sample size is large and ? is known. B-The standard normal, since the sample size is large and ? is known. C-The…

A community college Math instructor feels that the average age of community college students decreased since they started teaching 25 years ago.  Looking up data from the year the instructor started teaching, the mean age of community college students was 24.3 years old, with a population standard deviation of 2.2 years.  The Math instructor took a sample of 40 of their current community college students and found that the sample had a mean age of 23.7 years old.  Assume the population of ages of community college students is normally distributed and that the population standard deviation has remained the same. Test at the 5% significance level if the mean age of community college students is now less than 24.3 years old.   The question is attached.