# Probability Distribution vs Z

The clearest difference is review sentiment: Z at 100% against Probability Distribution's 33%. Z also leads on rating (5.0 vs 4.5) and in-app purchases (none vs 1). Probability Distribution's advantage is price (Free vs $2.99) and ads (none vs shown). On device support there is nothing between them.

Probability Distribution is free to download; Z costs $2.99 up front. Probability Distribution sells 1 one-off in-app purchase. Z asks for nothing beyond the download.

Z holds the better App Store score, 5.0 against 4.5. That said, the two scores are not equally well evidenced: Probability Distribution has 15 ratings behind it against 1, so its average is the more settled of the two. Written reviews point the same way: 33% of Probability Distribution's written reviews are positive against 100% of Z's.

Probability Distribution ships an update every 2 weeks, Z every 6 weeks. The most recent releases landed on September 26, 2026 and September 22, 2026 respectively.

## The numbers

| Metric | Probability Distribution | Z |
| --- | --- | --- |
| Price | **Free** | $2.99 |
| Rating | [4.5 (15 ratings)](https://appshunter.io/ios/app/probability-distribution/id6447695305/reviews) | **[5.0 (1 ratings)](https://appshunter.io/ios/app/z-table-statistics/id6738610691/reviews)** |
| Number of ratings | **15** | 1 |
| Positive reviews | 33.3% of reviews | **100.0% of reviews** |
| In-app purchases | Yes | **No** |
| Ads | **No** | Yes |
| Update frequency | **Every 2 weeks** | Every 6 weeks |
| Monetization | Paid | **Ad-supported** |
| Size | 7 MB | 32 MB |
| Requires iOS | 16.0 | **12.0** |
| Devices | iPhone, iPad | **iPhone, iPad, iPod** |
| Age rating | 4+ | 4+ |
| Developer | [Madiyar Aitbayev](https://appshunter.io/developer/1229466587) | [JanoGroup LLC](https://appshunter.io/developer/1781461557) |

## What reviewers say

### Probability Distribution

[App page](https://appshunter.io/ios/app/probability-distribution/id6447695305)

This app allows users to calculate probabilities and visualize various continuous and discrete probability distributions. It supports a wide range of common distributions and plans to add more in the future.

**Highlights:** Calculate probabilities, Visualize distributions, Normal (Gaussian) distribution, Binomial distribution, Poisson distribution, Exponential distribution

**Features:** macOS Compatibility, Family Sharing, Vision Pro support

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Unlock All Distributions | $2.99 | one-time |


### Z

[App page](https://appshunter.io/ios/app/z-table-statistics/id6738610691)

This app provides a quick and easy way for students and professionals to look up Z-scores and calculate corresponding probabilities. It features comprehensive Z-score tables and a user-friendly interface for efficient statistical analysis.

**Highlights:** Comprehensive Z-score tables, Fast probability calculation, User-friendly interface, Educational tool for statistics, Reference for data analysis

**Features:** macOS Compatibility

**In-app purchases:** none


## Frequently asked questions

### Is Probability Distribution free?

Probability Distribution is free to download, with in-app purchases available.

### Is Z free?

Z costs $2.99, with no in-app purchases.

### Which has better reviews, Probability Distribution or Z?

Z is rated higher. Probability Distribution averages 4.5 out of 5 from 15 ratings, while Z averages 5.0 from 1 ratings.

### Do Probability Distribution or Z have ads?

Z shows ads; Probability Distribution does not.

### Which is updated more often, Probability Distribution or Z?

Probability Distribution ships an update every 2 weeks, and Z every 6 weeks. Most recently, Probability Distribution was updated on September 26, 2026 and Z on September 22, 2026.

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*Compared by [AppsHunter](https://appshunter.io/) from daily US App Store data. Review summaries are generated from verbatim App Store reviews.*