Unit Test Answers

The heights of 1000 students at a local school were recorded and found to be approximated by the normal curve below. Which answer could represent the mean and standard deviation for these data?a.70, 5c.54, 4b.66, 8d.66, 4

The heights of a certain group of adult males was found to be normally distributed. The mean height is 170 cm with a standard deviation of 6 cm. In a group of 1200 of these males, about how many would be more than 164 cm tall?a.1173c.1010b.1146d.820

The average daily temperatures of a city in theUnited States were recorded for one year. The graph below shows the information. What is the median and the standard deviation of the average daily temperatures of this city?a.90; 36c.84; 6b.36; 6d.84; 8

In a certain normal distribution of scores, the mean is 40 and the standard deviation is 3. Find the z-score corresponding to a score of 54.a.4.67c.–4.67b.18.0d.13.33

Daytime high temperatures in New York in February are normally distributed with an average of 30.2º and a standard deviation of 8.5º.Estimate the probability that the temperature on a given day in February is 22º or lower.a.0.23c.0.815b.0.48d.0.16

Opal is collecting data on water levels in different parts of town. She notices that her sample data has a low-value outlier. Which statement must be true?

A supervisor finds the mean number of miles that the employees in a department live from work. He finds and . Which statement must be true?

A gymnastics coach records the scores of a gymnast and develops the probability distribution below. What is the probability the gymnast scores a 9 or 9.5?Probability DistributionGymnastics Score: XProbability: P(X)50.025.50.0260.066.50.170.167.50.1480.188.50.189?9.50.02

A simple random sample of size n is drawn from a normally distributed population, and the mean of the sample is , while the standard deviation is s. What is the 90% confidence interval for the population mean? Use the table below to help you answer the question.Confidence Level90%95%99%z*-score1.6451.962.58

A sample of restaurants in a city showed that the average cost of a glass of iced tea is $1.25 with a a standard deviation of 7¢. Three of the restaurants charge 95¢, $1.00, and $1.35. Determine the z-value for each restaurant.

The times taken to assemble a clock at a factory are approximately normally distributed with a given mean = 3 hr and standard deviation = 0.5 hr. What percentage of the times are between 2 hr and 4 hr?

A normal distribution of data has a mean of 90 and a standard deviation of 18. What is the approximate z-score for the value 64?

The distribution of the values of a population is shown below, and a simple random sample is drawn from the population. Based on this information alone, can the sample be used to make inferences about the population?

The proportions of multiple samples of registered voters who vote are normally distributed, with a mean proportion of 0.38 and a standard deviation of 0.0485. What is the probability that a sample chosen at random has a proportion of registered voters who vote between 0.37 and 0.39? Use the portion of the standard normal table below to help answer the question.zProbability0.000.50000.040.51600.210.58320.370.64430.380.64810.390.65171.000.8413

A scientist calculated the mean and standard deviation of a data set to be and . She then found that she was missing one data value from the set. She knows that the missing data value was exactly 3 standard deviations away from the mean. What was the missing data value?