fix typo: preceeding -> preceding

CHANGES.md

@@ -131,7 +131,7 @@ The [d3.range](https://github.com/d3/d3-array/blob/master/README.md#range) metho
 
 The method signature for optional accessors has been changed to be more consistent with array methods such as [*array*.forEach](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/forEach): the accessor is passed the current element (*d*), the index (*i*), and the array (*data*), with *this* as undefined. This affects [d3.min](https://github.com/d3/d3-array/blob/master/README.md#min), [d3.max](https://github.com/d3/d3-array/blob/master/README.md#max), [d3.extent](https://github.com/d3/d3-array/blob/master/README.md#extent), [d3.sum](https://github.com/d3/d3-array/blob/master/README.md#sum), [d3.mean](https://github.com/d3/d3-array/blob/master/README.md#mean), [d3.median](https://github.com/d3/d3-array/blob/master/README.md#median), [d3.quantile](https://github.com/d3/d3-array/blob/master/README.md#quantile), [d3.variance](https://github.com/d3/d3-array/blob/master/README.md#variance) and [d3.deviation](https://github.com/d3/d3-array/blob/master/README.md#deviation). The [d3.quantile](https://github.com/d3/d3-array/blob/master/README.md#quantile) method previously did not take an accessor. Some methods with optional arguments now treat those arguments as missing if they are null or undefined, rather than strictly checking arguments.length.
 
-The new [d3.histogram](https://github.com/d3/d3-array/blob/master/README.md#histograms) API replaces d3.layout.histogram. Rather than exposing *bin*.x and *bin*.dx on each returned bin, the histogram exposes *bin*.x0 and *bin*.x1, guaranteeing that *bin*.x0 is exactly equal to *bin*.x1 on the preceeding bin. The “frequency” and “probability” modes are no longer supported; each bin is simply an array of elements from the input data, so *bin*.length is equal to D3 3.x’s *bin*.y in frequency mode. To compute a probability distribution, divide the number of elements in each bin by the total number of elements.
+The new [d3.histogram](https://github.com/d3/d3-array/blob/master/README.md#histograms) API replaces d3.layout.histogram. Rather than exposing *bin*.x and *bin*.dx on each returned bin, the histogram exposes *bin*.x0 and *bin*.x1, guaranteeing that *bin*.x0 is exactly equal to *bin*.x1 on the preceding bin. The “frequency” and “probability” modes are no longer supported; each bin is simply an array of elements from the input data, so *bin*.length is equal to D3 3.x’s *bin*.y in frequency mode. To compute a probability distribution, divide the number of elements in each bin by the total number of elements.
 
 The *histogram*.range method has been renamed [*histogram*.domain](https://github.com/d3/d3-array/blob/master/README.md#histogram_domain) for consistency with scales. The *histogram*.bins method has been renamed [*histogram*.thresholds](https://github.com/d3/d3-array/blob/master/README.md#histogram_thresholds), and no longer accepts an upper value: *n* thresholds will produce *n* + 1 bins. If you specify a desired number of bins rather than thresholds, d3.histogram now uses [d3.ticks](https://github.com/d3/d3-array/blob/master/README.md#ticks) to compute nice bin thresholds. In addition to the default Sturges’ formula, D3 now implements the [Freedman-Diaconis rule](https://github.com/d3/d3-array/blob/master/README.md#thresholdFreedmanDiaconis) and [Scott’s normal reference rule](https://github.com/d3/d3-array/blob/master/README.md#thresholdScott).