Floretta, a pitcher, claims that her pitch speed is less than 46 miles per hour, on average. Several of her teammates do not believe her, so she decides to do a hypothesis test, at a 5% significance level, to persuade them. She throws 24 pitches. The mean speed of the sample pitches is 37 miles per hour. Floretta knows from experience that the standard deviation for her pitch speed is 5 miles per hour.

H0: μ≥46; Ha: μ<46
α=0.05 (significance level)
What is the test statistic (z-score) of this one-mean hypothesis test, rounded to two decimal places?