Which is one reason that factory work was dangerous in the 1800s?
a)machines were too difficult for workers to use.
b)there were not enough workers to operate large machines.
c)most machines had few safety features.
d)there were not enough machines to meet demand for products.

a) The null and alternative hypotheses:

H0 : u ≤ 14

H1 : u > 14

This is a right tailed test.

Let's find test statistics, z

P-value:

Using the standard normal table, NORMSDIST(3.0641) = 0.99889

P(Z>3.0641) = 1 - 0.99889

P(Z>3.0641) = 0.00111

Pvalue = 0.00111

At a significance level of 0.05.

Since pvalue, 0.00111 is less than significance level, 0.05, we reject null hypothesis, H0.

b) Test the hypothesis of part a using the critical-value approach at α = .05

At α = 0.05, (1 - 0.05) = 0.95

Using the standard normal table, the critical value at 0.95 is 1.65.

Reject null hypothesis H0, since Zstat 3.0641 is greater than Zcritical, 1.65.