The economist would like to test the claim that the percent of thirty-year fixed-rate mortgage loans that have a 4.75 percent interest rate is less than 22%. Sample size =40 thirty-year fixed-rate mortgage loans
Sample proportion =0.125

Calculate the test statistic using the formula
z0=p′−p0p0⋅(1−p0)n‾‾‾‾‾‾‾√

where:

p′ = sample proportion,
n = sample size, and
p0 = population proportion under the null hypothesis
Round your answer to 2 decimal places.