Answer:
The solution is the interval (-∞,5]
Step-by-step explanation:
we have
The solution is the interval -----> (-∞,5]
All real numbers less than or equal to 5
In a number line the solution is the shaded area at left of x=5 (close circle)
see the attached figure
Answer:
Yes. The data provide enough evidence to support the claim that the mean weight of one-year-old boys is greater than 25 pounds.
P-value=P(t>2.84)=0.0024
Step-by-step explanation:
Hypothesis test on the population mean.
The claim is that the mean weight of one-year-old boys is greater than 25 pounds.
Then, the null and alternative hypothesis are:
The significance level is α=0.05.
The sample size is n=354. The sample mean is 25.8 pounds and the sample standard deviation is 5.3 pounds. As the population standard deviation is estimated from the sample standard deviation, we will use a t-statistic.
The degrees of freedom are:
The t-statistic is:
For a right tailed test and 353 degrees of freedom, the P-value is:
As the P-value is smaller than the significance level, the effect is significant and the null hypothesis is rejected.
There is enough evidence to support the claim that the mean weight of one-year-old boys is greater than 25 pounds.