Answer:
63 m
Step-by-step explanation:
We are given the following in the question:
Average speed of swimming = 45 m/min
Time = 1 minute 24 seconds
Converting time into minutes:
Formula:
Putting values, we get.
Thus, Alex swims for 63 m in 1 minute and 24 seconds.
Correct question:
Thompson and Thompson is a steel bolts manufacturing company. Their current steel bolts have a mean diameter of 131 millimeters, and a standard deviation of 7 millimeters. If a random sample of 31" steel bolts is selected, what is the probability that the sample mean would differ from the population mean by more than 1.9 millimeters? Round your answer to four decimal places.
Answer:
0.1310
Step-by-step explanation:
Given:
Sample size, n = 31
mean, u = 131
X - u = 1.9
If a random sample of 31 steel bolts is selected, the probability that the sample mean would differ from the population mean by more than 1.9 millimeter, would be determined by:
Z = 1.51
Probability =
P(|Z| > 1.51) =
P(Z < -1.51) + P(Z > 1.51)
= P(Z < -1.51) + 1 - P(Z > 1.51)
Using the standard normal table:
= NORMDIST(-1.51) = 0.0655;
NORMDIST(1.51) = 0.9345
Thus,
P = 0.0655 + 1 - 0.9345
= 0.1310