Ameteorologist is studying the speed at which thunderstorms travel. a sample of 10 storms are observed. the mean of the sample was 12.2 mph and the standard deviation of the sample was 2.4. what is the 95% confidence interval for the true mean speed of thunderstorms?

The 95% confidence interval for the true mean speed of thunderstorms is [10.712, 13.688].

Step-by-step explanation:

Given information:

Sample size = 10

Sample mean = 12.2 mph

Standard deviation = 2.4

Confidence interval = 95%

At confidence interval 95% then z-score is 1.96.

The 95% confidence interval for the true mean speed of thunderstorms is

Where, is sample mean, z* is z score at 95% confidence interval, s is standard deviation of sample and n is sample size.

Therefore the 95% confidence interval for the true mean speed of thunderstorms is [10.712, 13.688].

2

step-by-step explanation:

94

step-by-step explanation:

average the numbers and use a variable to figure out the minimum to get a 90.

(79+94+91+92+x)/5=90

x = 94