Practice Math Statistics Problems and Master the Concepts

How do you find the geometric mean for the pair of numbers: -18, -36?

A fair coin is tossed 5 times. Find the probability that an even number of heads is tossed or no heads at all are tossed.

Annie Rice 2022-04-16

Last school year student body local university consisted of 35% freshmen 24% sophomores 26% juniors and 15% seniors. A sample of 300 Students taken from this year’s student body showed the following number of students in each classification. Freshmen 90 Sophomores 60 Juniors 90 Seniors 60 What is the expected frequency of seniors?
A- 65
B- 45
C - 35
D- 55

Zane Decker 2022-04-16

Katie must take five exams in a math class. If her scores on the first four exams are 76, 74, 90, and 88, what score must Katie get on the fifth exam for her overall mean to be at least 80?

Jewel Beard 2022-04-16

What is the difference between mean and average?

Aldo Fernandez 2022-04-16

What is the big advantage of some types of Chi-Square tests over a Two-Sample Test for Proportions?

Justine White 2022-04-16

What is stated by the null hypothesis for the chi-square test for independence?
a.There is no relationship between the two populations regarding the two variables.
b.Both variables have the same frequency distribution.
c.The two variables have different frequency distributions.
d.There is a relationship between the two populations regarding the two variables.

Camila Glenn 2022-04-16

What is a situation where you would test for homogeneity?

wadiad6qxb 2022-04-16

What if Dr changed his design and instead of just measuring the presence or absence of SAGC he changed the design to look at the following SAGC levels in his analysis: none, low, medium & high. Is there a Chi-Square test available to use? What is it and how is it different?

Aedan Berry 2022-04-16

What is a Chi-square test of independence? How is it helpful? Why is it used?

Justine White 2022-04-16

We say that the median is a resistant measure, whereas the mean is not a resistant measure. What's a resistant measure?

Efrain Watkins 2022-04-16

Weaknesses of Wald confidence interval for binomial distribution
A survey samples 1000 people, among which 500 say they will vote for A, 400 for B e 100 for C. Calculate a confidence interval for the proportion of people that will vote for A. What are the major weaknesses of the confidence interval you just calculated?
Let $A_{n} \sim Binom (n, p)$ . By the CLT,
$\sqrt{n} ({\overset{―}{A}}_{n} - p) x \to {d} N (0, p (1 - p))$
hence $\frac{\sqrt{n}}{\sqrt{p (1 - p)}} ({\overset{―}{A}}_{n} - p) x \to {d} N (0, 1)$
Since p is unknown, we approximate it with ${\overset{―}{A}}_{n}$ . It follows that, at $1 - α$ confidence,
$p \in {\overset{―}{A}}_{n} \pm z_{1 - \frac{α}{2}} \sqrt{\frac{{\overset{―}{A}}_{n} (1 - {\overset{―}{A}}_{n})}{n}}$
Since this confidence interval relies on the CLT, it gives poor results when n is small or p is very close to 0 or 1. But this is not the case here, as $n = 1000$ and ${\overset{―}{A}}_{n} = 0.5$ , so I fail to see what weaknesses the question is talking about?

Terrence Riddle 2022-04-16

What am I doing wrong in finding the confidence interval?
In a certain bio-engineering experiment, a successful outcome was achieved 60 times out of 125 attempts.
Construct a 95% confidence interval for the probability, p, of success in a single trial.
My answer:
We know that the confidence interval is:
$(p - k s, p + k s)$
Where s is the standard error.
I found the k value using Matlab code:
$k = ‖ \in ‖ v (0.975) = 1.9600$
Also: $p = \frac{60}{125} = 0.48$
Standard Error:
$s = \sqrt{\frac{p (1 - p)}{n}} = \sqrt{\frac{0.48 \cdot 0.52}{125}} = 0.04469$
We get the Confidence Interval:
$(0.392, 0.568)$
But my answer is wrong. Is there anything I'm missing out here?

delitzo1d4 2022-04-16

How do the different measures of center compare?

The probability of an event to happen in the next week is p and It is constant throughout the week What is the probability of this event to happen in the next 2 days?

Deja Vaughn 2022-04-15

Least squares regression analysis is a common method for modelling trip generation. What are the main assumptions of the least squares regression analysis in that context? Discuss with examples the consequences of violating two of these assumptions.

A standard deck of cards contains 52 cards. One card is selected from the deck. (a) Compute the probability of randomly selecting queen or nine . (b) Compute the probability of randomly selecting queen or nine or king. (c) Compute the probability of randomly selecting nine or diamond.

Frances Simon 2022-04-14

Find the mean for the following data set?
Values {10, 15, 20, 25, 30}
Frequency {5, 10, 7, 8, 2}

Ariel Collier 2022-04-14

Find CI for mean of linear regression with variance unknown
For the simple linear regression model:
$Y_{i} = β \cdot X_{i} + ϵ_{i}$
I want to find CI for $β x$ which is $E (Y_{i})$ when $x_{i} = x$ .
I find that $\hat{β} \sim N (β, \frac{σ^{2}}{\sum (X_{i}^{2})})$ , so the distribution of $β$ x is N( $β x, \frac{X^{2} σ^{2}}{\sum (X_{i}^{2})})$ . If the variance is known I can use $P (- z_{\frac{α}{2}} \leq \frac{\hat{β} x - β x}{x \frac{σ}{\sum} (x_{i}^{2})} \leq z_{\frac{α}{2}})$ .
If the variance is unknown, what unbiased estimator should I use for $σ^{2}$ ? Is it the sample variance? What is it in this case?

Eduardo Mclaughlin 2022-04-13

Maximum error in confidence interval
A sample of 40 cows is drawn to estimate the mean weight of a large herd of cattle. If the standard deviation of the sample is 96 kg, what is the maximum error in a 90% confidence interval estimate?

It’s not surprising that we encounter numerous ""I need help with statistics problems"" requests online because these are met everywhere, not only in economics or engineering. The majority of college statistics problems are also met in Sociology, Journalism, Healthcare, and Political Science. As long as you have statistics problems with solutions and answers, you will find solutions. Take a look at our college statistics math problems to find the answers. These will help college statistics problems be resolved. As you seek help with statistics problems, take your time to explore provided solutions and compare them with your initial instructions.

Improve Your Understanding of College Level Statistics Problems