12-hour pass
$8 / 12 hours
Sign in, then pay once. The clock starts when the payment goes through. Answers stop when the 12 hours end or the pass runs out of tokens, whichever comes first.
Ask the question. Get the answer.
Type statistics, algebra, calculus, and more in plain English. Dezmos gives you the answer and the steps right beside your work.
Question
A random sample of 64 students has a mean score of 78 with a standard deviation of 12. Find the 95% confidence interval for the population mean.
Dezmos
95% CI: (75.06, 80.94)
Standard error = 12 / √64 = 1.5
Margin of error = 1.96 × 1.5 = 2.94
78 ± 2.94 → (75.06, 80.94)
What students said.
★★★★★
Helped me ace my midterms lowk clutch
★★★★★
Literally looks alike the real thing nobody noticed
★★★★★
Nothing but helpful for my weekly quizs
From question to answer in seconds.
Question
In a survey of 250 students, 145 said they prefer online textbooks. Construct a 90% confidence interval for the true proportion.
Dezmos
90% CI ≈ (0.529, 0.631)
p̂ = 145/250 = 0.58
SE = √[0.58(0.42)/250]
Margin ≈ 0.051
No special syntax. Ask it the same way the question is written.
Built for the questions you actually get.
Paste the problem exactly as it’s written. Dezmos works through it and gives you a clear answer.
Didn’t understand it? Just ask again.
You
Why did you use 1.96?
Dezmos
Because a 95% confidence interval uses the critical z-value 1.96, which leaves 2.5% in each tail of the standard normal distribution.
You
explain that simpler
Dezmos
95% of the normal curve sits between −1.96 and +1.96, so we use 1.96 when calculating the interval.
One problem. As many follow-ups as you need.
What you can ask.
Statistics
Algebra
Calculus
Pricing
One answer is free. After that, a 12-hour pass is $8. Graphs stay on the page.
Nothing is charged until you finish card checkout.