# Statistics Quizzes

## Category:Statistics Quizzes

Statistics Quizzes

Quiz

1 / 1

If $$X$$ is a binomial random variable with parameters $$n = 10$$ and $$p = 0.3$$, then $$P(X \leq 3)$$ is:

The average score is 100%

0%

Quiz

To determine the correct answer, we use the central limit theorem, which states that the sampling distribution of the sample mean will be normally distributed if the sample size is sufficiently large (usually n > 30). We calculate the z-score for the sample mean of 1,210 hours and then find the corresponding probability from the standard normal distribution.

1 / 1

A manufacturing plant produces light bulbs that are supposed to have an average lifespan of 1,200 hours, with a standard deviation of 100 hours. If a random sample of 40 bulbs is taken from the production line, find the probability that the average lifespan of the bulbs in the sample will be more than 1,210 hours.

The average score is 50%

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Statistics Quiz with Solutions (10 questions)

Statistics Quiz with Solutions (10 questions)

1 / 10

The proportion of a population exhibiting a specific characteristic is $$p = 0.35$$. Determine the mean of the sample proportion derived from random samples of size $$n = 900$$.

2 / 10

For a standard normal variable $$Z$$, which of the following z-values satisfies the expression: $$P(Z \leq z) = 0.7734$$.

3 / 10

For the sample space $$S = \{a, b, c, d, e\}$$, identify the complement of $$B = \{b, d\}$$.

4 / 10

A random sample of size 169 is drawn from a population where the proportion possessing the desired trait is $$p = 0.48$$. Determine the standard error of the sample proportion.

5 / 10

For hypothesis tests involving a single population proportion with large samples, the test statistic is distributed according to:

6 / 10

A(n) _____ is a value that represents a characteristic of the sample data.

7 / 10

A numerical value produced by a stochastic process is referred to as a(n) _____.

8 / 10

A particular selection from a sample space is known as a(n) _____.

9 / 10

Determine the probability, $$P(-2.05 < Z < 1.96)$$, for a standard normal variable $$Z$$.

10 / 10

Calculate the expected value (mean) of a binomial distribution with parameters $$n = 10$$ and $$p = 0.3$$.

The average score is 95%

0%

Statistics Quiz with Solutions (10 Questions)

Statistics Quiz with Solutions (10 Questions)

1 / 10

Calculate the second quartile (Q2), also known as the median, of the given data set: {1.5, 2.3, 1.7, 3.6, 2.9, 4.2, 3.3}.

2 / 10

A journalist plans to interview an equal number of people in two cities to compare the proportions in each city that favor the proposal of privatization of government-controlled state public transportation. Let p1 and p2 be the true proportions of people of the two cities who are in favor of the proposal. Suppose it is desired to find a 99.9% confidence interval for estimating p1āp2 to within 0.08. Estimate the minimum equal number of people of each city that must be sampled to meet these criteria.

3 / 10

Determine the probability that, when a die is rolled eight times, the face showing two spots appears exactly twice.

4 / 10

An investor expects a return of 4% with a standard deviation of 6% on his savings. Use the empirical rule to find the probability of earning a return greater than 15% if the investment returns are normally distributed.

5 / 10

The deterministic part of the simple linear regression equation describes:

6 / 10

Assume that IQ scores follow a bell-shaped distribution with a mean of 100 and a standard deviation of 16. Use the empirical rule to find the percentage of people who scores between 52 and 148.

7 / 10

Lara orders five handmade mugs from an online site that claims that it averages only five damaged mug for every 50,000 mugs it produces. What is the probability that Lara's order contains one or more defective pieces?

8 / 10

A retailer wishes to estimate the difference in the average sales of a soft drink sold in two kinds of flavors, at 98% confidence and to within six dollars. Estimate the minimum equal sample sizes necessary if it is known that the standard deviations of the sales on these two flavors of the soft drink last week was $11.50 and$14.20.

9 / 10

A pair of balanced dice are rolled. What is the probability of not rolling doubles?

10 / 10

Construct a sample space for the experiment of tossing two distinguishable coins (h for heads and t for tails).

The average score is 38%

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Statistics Quiz with Solutions (5 Questions)

Statistics Quiz with Solutions (5 Questions)

1 / 5

A women's softball team plays soccer 2, 3, or 1 days a week. The probability that they play 2 days is 0.3, the probability that they play 3 days is 0.2, and the probability that they play 1 day is 0.5. Determine the average days per week that the team plays softball.

2 / 5

For a sample space S = {q, r, s, t}, suppose two events are identified as A = {q, t} and B = {r, s}. Also, P(q) and P(r) are 0.3 and 0.5 respectively and P(t) = 0.2. Calculate the P(A).

3 / 5

The heights of male students at a high school are measured. The average height is found to be 68 inches with a standard deviation of 2 inches. The distribution is approximately normal. If we draw a random sample of 16 boys from the school, what is the probability that the average height of these 16 boys is 71 inches or taller?

4 / 5

The heights of male high school students are measured. The average height is found to be 68 inches with a standard deviation of 2 inches. The distribution is approximately normal. If we draw a random sample of 16 boys from the school, then the standard deviation of the sample mean is:

5 / 5

Sean orders 20 pairs of gloves from an online clothing manufacturer. The site claims that it averages only 12 damaged pair of gloves for every 45,000 it produces. What is the probability that there are no perfect pieces in his order?

The average score is 100%

0%

Statistics Quiz with Solutions (5 Questions)

Statistics Quiz with Solutions (5 Questions)

1 / 5

A random sample of 8 students are selected from a class of 45 and their heights (in inches) were recorded as follows: {62.3, 68, 64, 66.1, 65.4, 61.8, 65.2, 68.6}. Compute the sample median.

2 / 5

A(n) _____ is any specific collections of objects of interest.

3 / 5

The _____ of a continuous random variable X is an assignment of probabilities to intervals of decimal numbers using a function f(x), called a density function.

4 / 5

For a standard normal variable Z, which of the following z values satisfies the expression: P(ZĀ  z) = 0.5636.

5 / 5

Consider a sample space S = {l, m, n, o}. Suppose P(l) and P(m) are each 0.3 and P(n) = 0.2. Find P(o).

The average score is 100%

0%

Statistics Quiz with Solutions (5 Questions)

Statistics Quiz with Solutions (5 Questions)

1 / 5

A random sample of 5 students are selected from a class of 35 and their heights (in inches) were recorded as follows: 63, 66.5, 62, 64.2, 70.8. Find the sample mean.

2 / 5

Identify the characteristic of the normal distribution.

3 / 5

The goodness-of-fit chi-square (ĻĀ²) test is always:

4 / 5

A(n) _____ is a number that summarizes some aspect of the population as a whole.

5 / 5

Find the indicated value of standard normal variable Z, $$z_{0.02}$$.

The average score is 100%

0%

Statistics Quiz with Solutions (5 Questions)

Statistics Quiz with Solutions (5 Questions)

1 / 5

Let $$A$$ and $$B$$ be two independent events. Their probabilities are $$P(A^c) = \frac{1}{5}$$, $$P(B) = \frac{1}{8}$$, and $$P(A | B) = \frac{4}{5}$$. Calculate $$P(A \cap B)$$.

2 / 5

In a study involving dogs, the researcher talks about the summary giving the sample size, sample sizes in select subgroups, and demographics such as the age, the proportion of subjects of each breed, and so on. Which branch of statistics does this signify?

3 / 5

Compute the sample median for the data: {-5, 4, 8, 5, 2, -1, 3, - 6}

4 / 5

Consider a random sample of 300 students in a university, 75 of them declared that they like playing football. Construct a 99% confidence interval for the proportion of all students who would like to play football.

5 / 5

Which of the following is the $$F_{0.025}$$ test statistic value for $$df_1 = 5$$ and $$df_2 = 7$$?

The average score is 100%

0%

Statistics Quiz with Solutions (10 Questions)

Statistics Quiz with Solutions (10 Questions)

1 / 10

In a random sample of size 700, 425 have the characteristic of interest. Identify the statement that justifies why one interval is longer than the other.

2 / 10

The probability distribution of a statistic is called its _____.

3 / 10

Which of the following data sets represents a population?

4 / 10

In order to get promoted to the next grade, a student is required to score above 55 in the final test. Assume the scores to be normally distributed with a mean of 60 and a standard deviation of 5.5. Calculate the percentage of students who will be promoted to the next grade.

5 / 10

The measurements of sample elements are collectively called the _____ data.

6 / 10

In which of the following situations is a census preferred over a sample?

7 / 10

Two hundred randomly selected women in a certain city, including those who are working, were asked the time they spend in the beauty salon for each visit. The average time was 44 minutes with a standard deviation of 16 minutes. Construct an 80% confidence interval for the mean time spent in the salon by all the women in the city.

8 / 10

For a value x in a data set, if P percent of the values are less than or equal to x, then x is called the _____.

9 / 10

Given a population proportion $$p = 0.56$$ and a random sample of size $$n = 120$$, calculate the probability that the sample proportion $$\hat{p}$$ is less than or equal to $$0.6$$.

10 / 10

Which of the following is not a random experiment?

The average score is 100%

0%

Statistics Quiz with Solutions (5 Questions)

Statistics Quiz with Solutions (5 Questions)

1 / 5

Sean orders 20 pairs of gloves from an online clothing manufacturer. The site claims that it averages only 12 damaged pair of gloves for every 45,000 pair it produces. What is the probability that there are no defective pieces in his order?

2 / 5

_____ is the most frequently occurring value in a sample data set.

3 / 5

The standard deviation of the sample mean is _____ the standard deviation of the population when the sample size is 2.

4 / 5

Find the range of the data set {5, 6, 3, 7, 8}.

5 / 5

The probability of winning a certain video game is 0.10. If Jeff plays the game 10 times, what is the probability that he will win at most once?

The average score is 40%

0%

Statistics Quiz with Solutions (5 Questions)

Statistics Quiz with Solutions (5 Questions)

1 / 5

For the data set {1.5, 2.3, 1.7, 3.6, 2.9, 4.2} find the second quartile, Q2.

2 / 5

A random sample of 100 male students is drawn from a particular class. The mean and standard deviation of heights of all male students in the college are 70 inches and 2 inches respectively. Calculate the standard deviation of the sample mean.

3 / 5

_____ random variables arise from a counting process.

4 / 5

A random variable is called _____ if its possible values contain a whole interval of numbers.

5 / 5

A random sample of 7 patients are selected from a group of 25 and their cholesterol levels were recorded as follows:
128, 127, 153, 144, 132, 120, 115.Ā Find the sample mean.

The average score is 100%

0%

Statistics Quiz with Solutions (5 Questions)

Statistics Quiz with Solutions (5 Questions)

1 / 5

Which of the following is not a random variable?

2 / 5

A kindergarten teacher wishes to estimate, to within 3 minutes, the mean time a child takes to arrange a jigsaw puzzle in the class with 90% confidence. Estimate the minimum size of sample required if the standard deviation of arrange times for the other kindergarten class is 4.2 minutes.

3 / 5

The observed significance of a test of hypotheses is the area of the tail of the distribution cut off by the _____.

4 / 5

A continuous random variable X has a normal distribution with mean 50. The probability that X takes a value greater than 55 is 0.25. Using this information and the symmetry of the density function, which of the following is the probability that X takes a value less than 45?

5 / 5

A sample of size 25 drawn from a normally distributed population has a sample mean 12 and a sample standard deviation 5. Construct an 80% confidence interval for the population mean.

The average score is 100%

0%

Statistics Quiz with Solutions (5 Questions)

Statistics Quiz with Solutions (5 Questions)

1 / 5

A fair die is rolled. What is the probability that the number rolled is less than three?

2 / 5

Consider two mutually exclusive events, G and H. Then, we have $$P(G | H)$$ = _____.

3 / 5

For large sample tests concerning a single population proportion, the null hypothesis will have the form $$H_0: p = p_0$$ where $$p_0$$ is some specific number _____

4 / 5

A restaurant owner wishes to estimate, to within 55 seconds, the mean time taken to serve food to customers with 99% confidence. In the past, the standard deviation of serving time has been about 2.5 minutes. Estimate the minimum size of the sample required.

5 / 5

_____ is the number of times a value x appears in a data set.

The average score is 100%

0%

Statistics Quiz with Solutions (6 Questions)

Statistics Quiz with Solutions (6 Questions)

1 / 6

For the data set: {1.5, 2.3, 1.7, 3.6, 2.9, 4.2}, identify the percentile for the value 2.9.

2 / 6

As the sample size of a random sample increases, the standard deviation of the sample mean _____.

3 / 6

A(n) _____ is a number or attribute computed for each member of a population or of a sample.

4 / 6

A pair of balanced dice are rolled. What is the probability of not rolling doubles?

5 / 6

A(n) _____ is any subset or subcollection of the population.

6 / 6

A random variable $$X$$ has the uniform distribution on the interval $$[0, 1]$$: the density function is $$f(x) = 1$$ if $$x$$ is between 0 and 1, and $$f(x) = 0$$ for all other values of $$x$$. What is the probability that $$X$$ assumes a value greater than 0.90?