The graph below displays a fire department’s response time, which measures the time from when the alarm is sounded at the firehouse to the time the first fire engine leaves the station. A histogram titled Fire Department Response Times has response time (seconds) on the x-axis and relative frequency on the y-axis. 20 to 30, 0.07; 30 to 40, 0.08; 40 to 50, 0.2; 50 to 60, 0.32; 60 to 70, 0.18; 70 to 80, 0.13; 80 to 90, 0.04.

Which interval accounts for the lowest percentage of response times?

20–30 seconds
30–40 seconds
70–80 seconds
80–90 seconds

I think its (D), 80-90 seconds. Someone check me.

At wind speeds above 1000 centimeters per second (cm/sec), significant sand-moving events begin to occur. wind speeds below 1000 cm/sec deposit sand and wind speeds above 1000 cm/sec move sand to new locations. the cyclic nature of wind and moving sand determines the shape and location of large dunes. at a test site, the prevailing direction of the wind did not change noticeably. however, the velocity did change. fifty-nine wind speed readings gave an average velocity of x = 1075 cm/sec. based on long-term experience, σ can be assumed to be 245 cm/sec. (a) find a 95% confidence interval for the population mean wind speed at this site. (round your answers to the nearest whole number.) lower limit cm/sec upper limit cm/sec