Clinic adult resting heart rates are approximately normal with mu = 72 beats/min and sigma = 8 beats/min. About what proportion is between 64 and 80 beats/min?

Heights of students in a school are approximately normal with mu = 170 cm and sigma = 6 cm. About what proportion is between 158 cm and 182 cm?

Laptop battery lives are approximately normal with mu = 10 h and sigma = 1.5 h. About what proportion is between 5.5 h and 14.5 h?

Medicine bottle volumes are approximately normal with mu = 100 mL and sigma = 5 mL. About what proportion of bottles hold more than 110 mL?

Morning commute times are approximately normal with mu = 30 min and sigma = 5 min. About what proportion of commutes take less than 25 min?

Tomato masses are approximately normal with mu = 120 g and sigma = 10 g. About what proportion is between 120 g and 130 g?

Semester exam scores are approximately normal with mu = 75 and sigma = 10. About what proportion of scores is between 55 and 95?

Greenhouse temperatures are approximately normal with mu = 22 °C and sigma = 2 °C. About what proportion of readings are above 28 °C?

Aquarium fish lengths are approximately normal with mu = 12 cm and sigma = 2 cm. What is the z-score for a 15 cm fish, to two decimals?

Placement exam scores are approximately normal with mu = 500 and sigma = 100. What is the z-score for a score of 430, to two decimals?

Cereal box masses are approximately normal with mu = 350 g and sigma = 5 g. What is the z-score for a box with mass 342.5 g, to two decimals?

Machine cycle times are approximately normal with mu = 18 s and sigma = 3 s. What is the z-score for a 24 s cycle, to two decimals?

Seedling heights are approximately normal with mu = 30 cm and sigma = 4 cm. What is the z-score for a 26 cm seedling, to two decimals?

Package delivery times are approximately normal with mu = 4.0 days and sigma = 0.5 days. What is the z-score for 5.25 days, to two decimals?

Pulse recovery times are approximately normal with mu = 90 s and sigma = 15 s. What is the z-score for 75 s, to two decimals?

Tablet battery lives are approximately normal with mu = 8.0 h and sigma = 1.2 h. What is the z-score for 9.5 h, to two decimals?

Maya scored 88 on biology, where mu = 76 and sigma = 8. Leo scored 72 on chemistry, where mu = 65 and sigma = 5. Who scored higher relative to the class?

A pumpkin is 4.2 kg with mu = 3.6 kg and sigma = 0.4 kg. A melon is 6.0 kg with mu = 5.0 kg and sigma = 0.5 kg. Which fruit is farther above its crop mean?

Nina ran 48 s where mu = 54 s and sigma = 3 s. Omar ran 19 s where mu = 22 s and sigma = 2 s. For events where lower time is better, who was faster relative to the event?

Noel scored 680 on an exam with mu = 620 and sigma = 40. Gia scored 31 on a quiz with mu = 26 and sigma = 3. Who scored higher relative to the group?

Use the shaded normal curve for carton fill amounts measured in mL. About what proportion is shaded?

The shaded normal curve shows tablet battery life measured in hours. About what proportion is shaded?

A normal curve for seed mass measured in grams is shaded. About what proportion is shaded?

Use the labeled normal curve for package weights measured in grams. About what proportion is shaded?

The normal curve shows bus wait times measured in minutes, and part of the curve is shaded. About what proportion is shaded?

A shaded normal curve gives soil moisture readings measured in units. About what proportion is shaded?

Bolt diameters are normal with mu = 10.00 mm and sigma = 0.05 mm. Given standard normal areas below z = -1 is 0.1587 and below z = 2 is 0.9772, find P(9.95 < X < 10.10) to three decimals.

Exam finish times are normal with mu = 50 min and sigma = 8 min. Given the area below z = 1.5 is 0.9332, what is P(X > 62) to three decimals?

Peach masses are normal with mu = 150 g and sigma = 12 g. Given areas below z = -0.5 and z = 2 are 0.3085 and 0.9772, find P(144 < X < 174) to three decimals.

Juice bottle fills are normal with mu = 250 mL and sigma = 4 mL. Given the area below z = -1.5 is 0.0668, what is P(X < 244) to three decimals?

Phone battery lives are normal with mu = 10 h and sigma = 2 h. Given areas below z = -1 and z = 1 are 0.1587 and 0.8413, find P(8 < X < 12) to three decimals.

Plant heights are normal with mu = 40 cm and sigma = 5 cm. Given the area below z = 2 is 0.9772, what is P(X > 50) to three decimals?

Delivery times are normal with mu = 34 min and sigma = 6 min. The 90th percentile of the standard normal is z = 1.28. The slowest 10% take longer than what time?

Soup serving temperatures are normal with mu = 60 °C and sigma = 4 °C. The 10th percentile of the standard normal is z = -1.28. What temperature marks the coolest 10%?

Scholarship scores are normal with mu = 500 and sigma = 80. The 95th percentile of the standard normal is z = 1.645. What score starts the top 5%, to one decimal?

Water bottle fills are normal with mu = 500 mL and sigma = 10 mL. The middle 90% ends at z = 1.645 on the upper side. What upper fill value ends that middle 90%, to one decimal?

Calf masses are normal with mu = 40 kg and sigma = 5 kg. The 25th percentile of the standard normal is z = -0.67. What calf mass is the 25th percentile, to one decimal?

Use the histogram of 80 backpack masses. A proposed normal model for these masses has mu = 6 kg and sigma = 1 kg. Is the normal model reasonable?

A histogram of 100 clinic wait times is shown. A normal model with mu = 18 min and sigma = 10 min is proposed. Is it reasonable for the wait times?

The histogram shows 90 commute distances. A normal model with mu = 16 km and sigma = 9 km is proposed. Should it be used for these commute distances?