Answer:
Step-by-step explanation:
Both 115 and 145 mph are above the mean. Draw a normal curve and mark these speeds. 115 mph is 1 standard deviation above the mean; 130 would be 2 standard deviations above the mean; and 145 would be 3 s. d. above it.
We need to find the area under the standard normal curve between 115 and 145. This is equivalent to the area under the standard normal curve between z = 1 and z = 3.
I used my TI-83 Plus calculator's DISTR function "normalcdf(" to calculate this area: normalcdf(1, 3) = 0.1573.
The area between z = 1 and z = 3 is 0.1573. In other words, the percentage of serves that were between 115 and 145 mph was 15.73%.
Answer is to your question is A
The answer is R= {-7, 1, 9, 17}. All you have to do is plug in the numbers (the domain) into the equation.
<span>Answer:
Calculating the t test statistic
t = (xbar - mu)/(s/sqrt(n))
t = (4.40-4.66)/(0.28/sqrt(6))
t = -2.27452618972722
t = -2.275
The t test statistic is approximately -2.275</span>
