Cadmium, a heavy metal, is toxic to animals. Mushrooms, however, are able to absorb and accumulate cadmium at high concentrations. Some governments have a safety limit for cadmium in dry vegetables at 3.2 parts per million (ppm). A hypothesis test is to be performed to decide whether the mean cadmium level in a certain mushroom is less than the government's recommended limit. Complete parts (a) through (c) below.
a. Determine the null hypothesis.
$\mathrm{H}_{0}: \mu \square \square \mathrm{ppm}$
(Type an integer or a decimal. Do not round.)
Answer
Final Answer: \( \boxed{H_{0}: \mu = 3.2 \, \text{ppm}} \)
Step 1 ：The null hypothesis in a statistical test is a statement that the value of a population parameter (such as proportion, mean, or standard deviation) is equal to some claimed value. In this case, we are testing whether the mean cadmium level in a certain mushroom is less than the government's recommended limit of 3.2 ppm. Therefore, the null hypothesis would be that the mean cadmium level in the mushroom is equal to the government's recommended limit.
Step 2 ：Final Answer: \( \boxed{H_{0}: \mu = 3.2 \, \text{ppm}} \)
