The average heights of a random sample of 400 people from a city is 1.75 m. It is known that the heights of the population are random variables that follow a normal distribution with a variance of 0.16. Determine the interval of 95% confidence for the average heights of the population. With a confidence level of 90%, what would the minimum sample size need to be in order for the true mean of the heights to be less than 2 cm from the sample mean?

A study showed that females’ body temperatures are approximately normally distributed with a mean of 98.40F, and a population standard deviation of 0.700F. Find the female body temperature at the 90th percentile.

A simple random sample of 34 men from a normally distributed population results in a standard deviation of 8.8 beats per minute. The normal range of pulse rates of adults is typically given as 60 to 100 beats per minute. If the range rule of thumb is applied to that normal range, the result is a standard deviation of 10 beats per minute. Use the sample results with a 0.05 significance level to test the claim that pulse rates of men have a standard deviation equal to 10 beats per minute. Complete parts (a) through (d) below. ... a. Identify the null and alternative hypotheses. Choose the correct answer below. O A. H: 0 10 beats per minute O B. H, o= 10 beats per minute H:o = 10 beats per minute H o<10 beats per minute O D. H, 62 10 beats per minute H o<10 beats per minute O C. H, o= 10 beats per minute H: 0 10 beats per minute b. Compute the test statistic. %3D (Round to three decimal places as needed.) c. Find the P-value. P-value = (Round to four decimal places as needed.) d. State…

a random sample of 30 students IQ scores have a mean score of 112.5. if the mean population IQ is 100 with a standard deviation of 15, assuming a to tail sampling. Determine the confidence interval of the sampling distribution, determine the variance of sampling distribution, is the mean IQ of the sample is within the acceptable values?

A simple random sample of 36 men from a normally distributed population results in a standard deviation of 11.8 beats per minute. The normal range of pulse rates of adults is typically given as 60 to 100 beats per minute. If the range rule of thumb is applied to that normal​ range, the result is a standard deviation of 10 beats per minute. Use the sample results with a 0.10 significance level to test the claim that pulse rates of men have a standard deviation equal to 10 beats per minute. Complete parts​ (a) through​ (d) below.       a. Identify the null and alternative hypotheses. Choose the correct answer below.     A. H0: σ≥10 beats per minute H1: σ<10 beats per minute   B. H0: σ≠10 beats per minute H1: σ=10 beats per minute   C. H0: σ=10 beats per minute H1: σ≠10 beats per minute   D. H0: σ=10 beats per minute H1: σ<10 beats per minute b. Compute the test statistic.   χ2=48.73448.734 ​(Round to three decimal places as​ needed.) c. Find…

A random sample of 10 subjects have weights with a standard deviation of 11.9848 kg . What is the variance of their weights ? Be sure to include the appropriate units with the result .

A simple random sample of 46 men from a normally distributed population results in a standard deviation of 9.6 beats per minute. The normal range of pulse rates of adults is typically given as 60 to 100 beats per minute. If the range rule of thumb is applied to that normal range, the result is a standard deviation of 10 beats per minute. Use the sample results with a 0.10 significance level to test the claim that pulse rates of men have a standard deviation equal to 10 beats per minute. Complete parts (a) through (d) below.

A simple random sample of 49 men from a normally distributed population results in a standard deviation of 11.4 beats per minute. The normal range of pulse rates of adults is typically given as 60 to 100 beats per minute. If the range rule of thumb is applied to that normal range, the result is a standard deviation of 10 beats per minute. Use the sample results with a 0.10 significance level to test the claim that pulse rates of men have a standard deviation equal to 10 beats per minute. Complete parts (a) through (d) below. a. Identify the null and alternative hypotheses. Choose the correct answer below. O A. Ho: o = 10 beats per minute O B. Ho: o# 10 beats per minute H1: 0+ 10 beats per minute H,:0 = 10 beats per minute O C. Ho: o2 10 beats per minute O D. Ho: 0= 10 beats per minute H1: o< 10 beats per minute H1:o< 10 beats per minute

Suppose a certain species bird has an average weight of = 3.85 grams. Based on previous studies, we can assume that the weights of these birds have a normal distribution with σ = 0.31 grams. Find the sample size necessary for a 98% confidence level with a maximal error of estimate E = 0.09 for the mean weights of the hummingbirds.

Aldo, a highway safety inspector, is concerned about the potential for accidents caused by boulders that fall down a sandstone cliff beside a main highway. As part of an accident simulator, Aldo models the boulders' weights using a normal distribution with a mean of 556 kg and a standard deviation of 100 kg find the percentage of boulders that weigh less than  520kg or more than 592kg according to the model.   .