Question Help ▼ Claim: The standard deviation of pulse rates of adult males is less than 11 bpm. For a random sample of 140 adult males, the pulse rates have a standard deviation of 9.8 bpm. Find the value of the test statistic. The value of the test statistic is (Round to two decimal places as needed.)

i already have answer in question A-D. please help me to solve the rest. topic is unkown standard deviation

Adult men have heights with a mean of 69.0 inches and a standard deviation of 2.8 inches. Find the z-score of a man 62 inches tall. (round to 2 decimal places)

The scores on a standardized test are normally distributed with a mean of 115 and standard deviation of 20. What test score is 2.2 standard deviations above the mean?

Blood pressure is distributed Normally, with a mean of 85 mm and a standard deviation of 20 mm. What fraction of the population has a blood pressure above 80 mm?

The mean score for first exam in your first organic chemistry class (section A) was 60, with a standard deviation of 5. Your score on the exam was 70. A. How many standard deviations above the mean is your score?

I need help with understanding standard deviation.  How to calculate it from the mean?