Which of the following statements below are correct about Student's t-models? Select all that are true (select all statements that are correct). O Approximately 68% of the data is within one standard deviation of the population mean. The t-model has a unin dal probability density function. The critical values determined through a t-model are influenced by changes in the sample size. As the degrees of freedom increase, the t-model will have a higher peak and larger spread. As the sample size decreases, the t-model begins to resemble the bimodal distribution more closely. The t-model has a multi-modal probability density function